The US vice-president has called on Ukraine and Russia to accept a US-led peace proposal that would see the conflict frozen roughly along the current frontlines and threatened that Washington would “walk away” if it was not accepted.

Speaking on a trip to India, JD Vance said there would have to be “some territorial swaps” to reach a deal in public comments that came as London hosted a Ukraine peace conference that the US secretary of state, Marco Rubio, had withdrawn from.

“We’ve issued a very explicit proposal to both the Russians and the Ukrainians, and it’s time for them to either say yes or for the United States to walk away from this process,” Vance said.

“The only way to really stop the killing is for the armies to both put down their weapons, to freeze this thing and to get on with the business of actually building a better Russia and a better Ukraine.”

The US proposal would mean “we’re going to freeze the territorial lines at some level close to where they are today,” Vance said, though he added there should be some adjustments. “Now, of course, that means the Ukrainians and the Russians are both going to have to give up some of the territory they currently own.”

The vice-president did not explicitly mention that US would recognise Crimea, seized by Moscow in 2014, as part of Russia but reports have suggested that the concession is also part of a proposal gradually being leaked into the public domain.

A ceasefire on the current frontlines has already been accepted in principle by Ukraine and its president, Volodymyr Zelenskyy, called again for an immediate halt to the three-year war. “In Ukraine, we insist on an immediate, full and unconditional ceasefire,” he said, adding that “stopping the killings is the number one task”.

Early on Wednesday, nine people were reportedly killed when a Russian drone hit a bus carrying workers in the Ukrainian city of Marhanets – one of 134 large drones that Ukrainian authorities reported had attacked the country overnight.

But Russia’s demand that the US legally recognise its seizure of Crimea, a redrawing of borders by force, was rejected by Zelenskyy on Tuesday. “There is nothing new to mention or discuss. Ukraine will not recognise the occupation of Crimea,” he had said, adding that it would be incompatible with Ukraine’s constitution.

Though Ukraine has indicated it is willing to accept de facto Russian occupation of around a fifth of its territory, arguing that it will reunite the country by diplomatic means eventually, it has refused to accept what would be a domestically unpopular partition, even if the recognition was done by the US.

Other anticipated elements of the deal are that Ukraine would be prevented by a US veto from joining Nato, a point largely accepted by a reluctant Kyiv. But another that future security guarantees would be provided by a UK and French-led 30-country “coalition of the willing” has not been accepted by Russia.

Speaking to reporters on Wednesday, Putin’s spokesperson, Dmitry Peskov, said Russia continued to oppose the presence of European peacekeeping forces, which Ukraine sees as the only viable alternative to Nato membership for ensuring its security.

Peskov said there were “many nuances” surrounding negotiations to end the conflict in Ukraine and that the positions of the various parties involved had yet to be brought closer – suggesting, from a Russian perspective, that the deal was not yet agreed.

Britain had announced there would be a fresh round of peace talks in London on Wednesday, hosted by the foreign secretary, David Lammy, and to which counterparts from the US and Ukraine had been invited plus delegations from France and Germany.

Lammy had been hoping to bring together the US, Ukraine and Europe in the peace discussions on Wednesday and so maintain relationships between traditional allies even while the direct US-Russia talks continued.

But the British minister was embarrassed by Rubio’s sudden decision late on Tuesday not to turn up and by a rising chorus of leaks apparently from the US and Russia, designed to derail the discussions and to promote the idea that the most significant discussions are those taking place directly between Washington and Moscow.

Britain said the talks had been downgraded to the level of officials and the US said it would send its Ukraine envoy, Keith Kellogg, instead of Rubio. However, Kyiv decided it would nevertheless send a senior delegation led by Andriy Yermak, Zelenskyy’s chief of staff, plus the foreign minister, Andrii Sybiha, and the defence minister, Rustem Umerov.

Initial indications suggested Russia was willing to trade territory it does not control in Ukraine – in effect, fresh air – for a US recognition of its seizure of Crimea, in what would be a formal acknowledgment that it is possible to change borders by force, creating an extraordinary post-second world war precedent.

The Kremlin’s signals are carefully calibrated and almost certainly designed to make matters difficult for Zelenskyy. Ukraine’s leadership has repeatedly signalled – as Zelenskyy repeated on Tuesday – that it could not legally recognise the seizure of Crimea or any of its other territory that Russia occupies.

Russia may be banking on the idea that Ukraine is weary after more than three years of war and that its proposal is a reasonable counter to western suggestions, backed by the US, Ukraine and Europe, that there should be an immediate and full ceasefire to allow other wider negotiations to take place.

Indian security forces fanned out across the Himalayan region of Kashmir as the army and police launched a massive manhunt for the perpetrators of a militant attack on Tuesday that killed at least 26 tourists.

The search progressed as India’s defence minister said those who carried out and planned the Kashmir region’s worst attack on civilians in years would see a swift response, including those “behind the scenes”.

“Those responsible and behind such an act will very soon hear our response, loud and clear,” Rajnath Singh said in a speech in New Delhi, a day after gunmen killed 26 men.

“We won’t just reach those people who carried out the attack. We will also reach out to those who planned this from behind the scenes on our land.”

Tens of thousands of armed police and troops headed to the region, setting up checkpoints and searching vehicles, while many businesses remained closed after a call by religious and political figures.

“The search operation is currently in progress, with all efforts focused on bringing the attackers to justice,” the Indian army said in a statement.

A little-known militant group, the Kashmir Resistance, claimed responsibility for the attack. Posting on social media it expressed discontent that more than 85,000 “outsiders” had been settled in the region, spurring a “demographic change”.

The attack, reportedly involving four gunmen, took place in a meadow in the Pahalgam area of the scenic Himalayan federal territory. The dead people included 25 Indians and one Nepalese national, the worst attack on civilians in India since the 2008 Mumbai shootings.

The prime minister, Narendra Modi, cut short a two-day visit to Saudi Arabia and returned to New Delhi on Wednesday morning.

Modi held a meeting with his national security adviser, the foreign minister and other senior officials at the airport, and a special security cabinet meeting was called for later on Wednesday.

The attack is seen as a setback to what Modi and his Hindu nationalist Bharatiya Janata party have hailed as a significant achievement in revoking the semi-autonomous status Jammu and Kashmir enjoyed and bringing peace and development to the long-troubled Muslim-majority region.

Tuesday’s attack is being viewed as a major escalation in the regional conflict, in which attacks targeting tourists have been rare.

The last deadly incident took place in June 2024, when at least nine people were killed and 33 injured after militants caused a bus carrying Hindu pilgrims to plunge into a deep gorge.

In a fresh statement on Wednesday, the Kashmir Resistance said that those attacked on Tuesday “were not ordinary tourists; instead, they were linked to and affiliated with Indian security agencies”.

The attack prompted an immediate exodus of tourists from the region, with airlines operating extra flights from Srinagar, the summer capital of the territory. Local television showed tourists carrying their bags to taxis and filing out of a hotel in Srinagar.

“How can we continue our trip in such a situation?” Sameer Bhardwaj, a tourist from New Delhi, asked the news agency ANI. “We need to prioritise our safety. We can only travel if our minds are relaxed but everyone is tense here. So, we cannot continue to travel.”

Gulzar Ahmad, a taxi driver in Pahalgam, said: “This attack will impact our work, but we are more concerned about the loss of lives. No matter what we do in the future, our tourism industry has been stained by this attack. The perpetrators must receive exemplary punishment so that no one dares to commit such an act again.”

The attack occurred during a four-day visit to India by the US vice-president, JD Vance, who called it a “devastating terrorist attack”.

Donald Trump also expressed solidarity, writing on social media: “The United States stands strong with India against terrorism.”

Other global leaders, including the Russian president, Vladimir Putin, and the Italian prime minister, Giorgia Meloni, condemned the attack.

The UN secretary general, António Guterres, said: “Attacks against civilians are unacceptable under any circumstances.”

Omar Abdullah, the region’s top elected official, posted on social media: “It’s heartbreaking to see the exodus of our guests from the [Kashmir] valley after yesterday’s tragic terror attack in Pahalgam. But at the same time, we totally understand why people would want to leave.”

He added that his administration had been directed to facilitate the smooth departure of tourists.

Abdullah recently stated in the regional assembly that 23 million tourists visited the region in 2024.

There has been an increase in the number of targeted killings of Hindus, including migrant workers from other Indian states, in the disputed Himalayan region since New Delhi unilaterally revoked Kashmir’s limited autonomy in 2019 by imposing a communication blockade and jailing activists and political leaders.

It split the state into two federally administered territories – Jammu and Kashmir, and Ladakh – and allowed local authorities to issue domicile certificates to outsiders, enabling them to apply for jobs and buy land. Since then, civil liberties and media freedom in the region have been severely curtailed.

While officials indicated they believed that Pakistani militant groups may be behind the attack they did not officially confirm the identities of the perpetrators or those killed.

Pakistan’s foreign office spokesperson, Shafqat Khan, issued a statement saying Pakistan was “concerned about the loss of tourists’ lives in the attack”, and extended condolences to the victims.

Three dozen members of the largest body representing British Jews are facing disciplinary action after signing an open letter criticising Israel over the war in Gaza.

Amid signs of deepening divisions among British Jews over the 18-month-old war, the Board of Deputies announced this week that all 36 signatories to the letter were now “subject to a complaints procedure” after “multiple complaints”.

One, Harriett Goldenberg, was suspended as vice-chair of the board’s international division pending the investigation. She was also asked to step back from her role on the executive until the conclusion of the investigation, according to the Jewish Chronicle.

A statement from the board said the letter was “not representative” of its policy on Israel. A special meeting of its executive committee was convened on Tuesday to “discuss the ramifications and consequences of this act”.

The committee voted unanimously to open a complaints procedure, which is expected to take at least four weeks, the board said.

The signatories to the letter, which was published by the Financial Times, said they could no longer “turn a blind eye or remain silent” over the war in Gaza. “Israel’s soul is being ripped out”, they said.

They added: “The inclination to avert our eyes is strong, as what is happening is unbearable, but our Jewish values compel us to stand up and to speak out.”

Since the start of the war, after the attacks by Hamas against Israelis on 7 October 2023, statements by the Board of Deputies have been broadly supportive of the Israeli government.

After the executive committee meeting this week, Phil Rosenberg, the board’s president, said: “We take alleged breaches of the code of conduct very seriously … The Board of Deputies is clear: only our democratically elected honorary officers and authorised staff speak on behalf of the organisation.”

Last week, Michael Wegier, the board’s chief executive, said a group of deputies had “aired their views in a national publication, specifically in their capacity as deputies, leading them to an incorrect assumption by a significant number of people in our community and beyond that this group is putting forward the board’s official position, which it is not.”

In an article in the Jewish Chronicle, he added: “Taking the legitimate and often painful debate within our community to the letters pages of national newspapers, and sowing confusion about the position of the community as a whole, is a shortsighted and dangerous precedent.”

Most of the letter’s signatories belong to Reform, Liberal or Masorti communities. Many of the complaints reportedly came from members of the United Synagogue, the largest communal denomination in the UK.

Goldenberg has been approached for comment.

Sharon Osbourne has urged US authorities to revoke work visas for Kneecap after the Irish language rap group used a performance at Coachella to denounce Israeli attacks on Gaza.

The TV presenter accused the band of hate speech and supporting terrorist organisations and said it should not be allowed to perform in the US. “I urge you to join me in advocating for the revocation of Kneecap’s work visa,” she exhorted followers on X on Tuesday.

Fox News commentators also condemned the band and accused it of bringing “Nazi Germany” sentiments to America.

Kneecap scorned the Fox News comments and posted supportive messages from fans, saying it had received thousands of such endorsements as well as “hundreds of violent Zionist threats”. Almost all the concerts of a US tour scheduled for October have sold out, it added.

The trio, Móglaí Bap and Mo Chara from Belfast and DJ Próvaí from Derry, have built a following in the US with a mix of Irish republican totems, punk spirit and a film that stormed last year’s Utah film festival.

During their set last weekend at Coachella, the California desert music festival, Mo Chara said Britain had persecuted Irish people but not bombed them from the skies. “The Palestinians have nowhere to go.”

The performers led the audience in chants of “free, free Palestine” and screened pro-Palestinian messages on to screens. “Israel is committing genocide against the Palestinian people,” said one. “It is being enabled by the US government who arm and fund Israel despite their war crimes,” said another. The last used an expletive against Israel.

Osbourne, a judge on the TV show America’s Got Talent, said the festival had “compromised its moral and spiritual integrity” by allowing Kneecap and Green Day to denounce Israel over the 18-month war.

“Music’s primary purpose is to unite people. It should not be a venue for promoting terrorist organisations or spreading hate”, she said, singling out Kneecap’s “aggressive” political statements.

“This band openly support terrorist organisations. This behaviour raises concerns about the appropriateness of their participation in such a festival and further shows they are booked to play in the USA.”

Fox News commentators compared the band’s comments to Nazi Germany, with one saying the band should be removed from “authority positions” and that the “values of education” should be re-instilled.

Kneecap posted a clip of the segment and said the commentator’s admission that she had not previously heard of the band was the “only part of this shite that made any sense”.

The group said they had planned to denounce “US-backed genocide in Gaza” at an earlier performance in Coachella, on 11 April, but that the comments did not appear on the screen. The band also complained that the festival’s livestream did not carry a chant celebrating the death of Margaret Thatcher.

As more develops about the US defense secretary, Pete Hegseth, and his repeated disclosures of sensitive military intelligence in unsecured Signal group chats, there are growing concerns his behavior has weakened the Pentagon in the eyes of its foreign adversaries and made him and his entourage a top espionage target.

Allies, already concerned by Donald Trump’s aggressive tariffs, have also begun to see the US as an intelligence-sharing liability. There are fears that the mounting firings and leak inquiries in Hegseth’s orbit, along with his inability to manage these internal crises, exposes the entire global US war footing – especially, if a geopolitical and external crisis comes across his desk.

“[What if] a foreign entity, whether it be a state actor or non-state actor, is able to intercept the movements of troops or department personnel, or something like that, capture them and hold them to ransom,” said Kristofer Goldsmith, an Iraq war veteran and CEO at Task Force Butler. “That kind of thing could very easily happen.”

Earlier in the week, news broke that Hegseth had personally created a Signal group chat including his wife, brother and about a dozen other people who he then texted highly sensitive information on active strikes in Yemen. Previously, he discussed similar intelligence in a group chat on the same app, which included top officials in the Trump administration and a journalist from the Atlantic.

Former officials serving in national security positions under Joe Biden’s administration also told the Guardian on background that the situation is perilous and that Hegseth has endangered the secrets of the defense department and the White House. One person said Russian and Chinese spies were no doubt directly targeting susceptible people in Hegseth’s inner circle.

Goldsmith, a threat intelligence expert, said there were many scenarios wherein a foreign government could gain access to those chats, without the need to directly compromise Hegseth’s devices.

“Pete Hegseth is texting his wife and his wife is posting on Instagram, clicks a link, and gets malware on her phone,” said Goldsmith, describing a hypothetical scenario. “Then the Chinese or the Iranians or the Russians just happen to be like, ‘Oh, shit, we’ve got Mrs Hegseth, [without] even targeting her.’”

To Goldsmith, Hegseth, who came into power on the heels of publicly characterizing the Pentagon as a “woke” shambles after years of ignoring “war fighters”, has already undermined the overall power of the US military in his months-long reign.

“These kinds of leaks, anticipating troop movements, anticipating attacks – those can put our adversaries in position to intercept pilots or convoys or ships, which could create an international incident,” he said. “It could mean a nuclear or a biological or a chemical crisis of some kind.”

Within the geopolitical competition between the US, Russia and China, assigning teams of capable intelligence agents trailing, hacking and spying on the every move of your top officials is an open secret. Protecting those officials and the sanctity of their communications from those interventions is a well-trodden and technical mission that calls in some of America’s most secretive agencies.

But if the advice, devices and apps provided to those officials go ignored, foreign adversaries have an opening.

Hegseth’s adherence to operational security, “opsec” for short among national security professionals, referring to the general tradecraft of preventing sensitive information from being leaked, has advertised to foreign adversaries how to compromise him.

“Well, they know what he’s operating on,” said Joe Plenzler, a retired veteran of the United States Marine Corps who served in the wars in Iraq and Afghanistan. “Signal is better than most other commercial apps, but it’s not military-grade encryption.”

Plenzler, who was a public affairs officer in the Iraq war under the former secretary of defense Gen James Mattis, a senior figure in Trump’s first administration, said he and his boss understood the importance of respecting the secrecy of communications in the field.

“If any officer or enlisted member had passed classified information over an unsecured or unauthorized [device], we would have been immediately removed [them] from our position, investigated, most likely prosecuted,” he said. “For an officer, it’s a career killer.”

Plenzler said Mattis told his subordinates: “‘When you’re leading marines you have to lead by example. The fastest thing that will crack the morale of any unit is the leader that says, ‘Do as I say, not as I do.’”

Plenzler added that Hegseth’s conduct was “inexcusable”, especially when divulging some of the kinds of sources and methods, gleaned from intelligence-gathering, that can put people’s lives in danger.

“What sources are getting burned when secrets get out? People are risking their lives to help the United States, to protect our citizens and our allies, and when these things go sideways, some people are very literally running for their lives,” he said. “When my former boss was sitting in the chair, I felt a lot better.”

On Monday, during the White House Easter egg roll event, Hegseth was chatty and defiant with the press in attendance.

“Signal chat controversy?” he said to reporters. “This is what the media does – they take anonymous sources from disgruntled former employees, and then they try to slash and burn people and ruin their reputations.”

Trump agreed, backing Hegseth.

“He’s doing a great job,” Trump said, dismissively, at the same event.

The leftwing junior partners in Spain’s socialist-led coalition government have called on the interior ministry to cancel a €6.6m (£5.7m) order for millions of bullets from an Israeli company, claiming the deal breaches coalition agreements and undermines efforts to hold Israel to account over its actions in Gaza.

Spain’s socialist prime minister, Pedro Sánchez, has been one of the most outspoken critics of Israel’s prosecution of the war in Gaza, questioning whether it is following international humanitarian law and calling the number of Palestinian deaths “truly unbearable”.

In October last year, the interior ministry announced it had cancelled the purchase of 15.3m bullets from an Israeli company because of the government’s “commitment to neither buying weapons from, nor selling weapons to, the state of Israel following the outbreak of armed conflict in Gaza”.

But it emerged on Wednesday that the purchase of the 9mm ammunition, which had been ordered on behalf of the Guardia Civil police force, was going ahead because the interior ministry had decided the contract was too far advanced and too expensive to cancel.

The apparent U-turn prompted an angry response from the Sumar platform, which was founded by Yolanda Díaz, Spain’s labour minister and one of the country’s three deputy prime ministers.

The platform described the contract as a “flagrant breach” of the commitments made within the government on suspending the buying of weapons from Israel and demanded its immediate cancellation. It also called on the socialist interior minister, Fernando Grande-Marlaska, to appear before MPs to explain what had happened.

“Our commitment to the Palestinian people is absolute,” the platform said in a statement. “That is why we have repeatedly called for a total embargo on the purchase of weapons from Israeli, for the breaking off of diplomatic relations with Israel, for the imposition of sanctions, and for the international criminal court to be supported in the arrest warrants it has issued for [Israeli prime minister Benjamin] Netanyahu and other members of his government and the Israeli army.”

Others within Sumar went further. Antonio Maíllo, the federal coordinator of the platform’s United Left group, said he and his colleagues would not tolerate “any part of the executive financing a genocidal state” and said the issue had provoked the worst crisis to date between Sumar and the socialists.

News that the contract would proceed came a day after Sumar dismissed Sánchez’s plans to invest €10.5bn to enable Spain to reach its long-delayed Nato commitment of spending 2% of its GDP on defence as “incoherent” and “absolutely exorbitant”.

Sources at the interior ministry said the department began looking into annulling the contract six months ago and decided to proceed with it on legal advice.

“Annulling the contract would have meant paying the company for the order without receiving the agreed materials, which are needed so that the Guardia Civil can fulfil its duties,” the sources said.

Despite the contract in question, they insisted the interior ministry shared the government’s commitment to not selling weapons to, or buying weapons from, Israel.

The leftwing junior partners in Spain’s socialist-led coalition government have called on the interior ministry to cancel a €6.6m (£5.7m) order for millions of bullets from an Israeli company, claiming the deal breaches coalition agreements and undermines efforts to hold Israel to account over its actions in Gaza.

Spain’s socialist prime minister, Pedro Sánchez, has been one of the most outspoken critics of Israel’s prosecution of the war in Gaza, questioning whether it is following international humanitarian law and calling the number of Palestinian deaths “truly unbearable”.

In October last year, the interior ministry announced it had cancelled the purchase of 15.3m bullets from an Israeli company because of the government’s “commitment to neither buying weapons from, nor selling weapons to, the state of Israel following the outbreak of armed conflict in Gaza”.

But it emerged on Wednesday that the purchase of the 9mm ammunition, which had been ordered on behalf of the Guardia Civil police force, was going ahead because the interior ministry had decided the contract was too far advanced and too expensive to cancel.

The apparent U-turn prompted an angry response from the Sumar platform, which was founded by Yolanda Díaz, Spain’s labour minister and one of the country’s three deputy prime ministers.

The platform described the contract as a “flagrant breach” of the commitments made within the government on suspending the buying of weapons from Israel and demanded its immediate cancellation. It also called on the socialist interior minister, Fernando Grande-Marlaska, to appear before MPs to explain what had happened.

“Our commitment to the Palestinian people is absolute,” the platform said in a statement. “That is why we have repeatedly called for a total embargo on the purchase of weapons from Israeli, for the breaking off of diplomatic relations with Israel, for the imposition of sanctions, and for the international criminal court to be supported in the arrest warrants it has issued for [Israeli prime minister Benjamin] Netanyahu and other members of his government and the Israeli army.”

Others within Sumar went further. Antonio Maíllo, the federal coordinator of the platform’s United Left group, said he and his colleagues would not tolerate “any part of the executive financing a genocidal state” and said the issue had provoked the worst crisis to date between Sumar and the socialists.

News that the contract would proceed came a day after Sumar dismissed Sánchez’s plans to invest €10.5bn to enable Spain to reach its long-delayed Nato commitment of spending 2% of its GDP on defence as “incoherent” and “absolutely exorbitant”.

Sources at the interior ministry said the department began looking into annulling the contract six months ago and decided to proceed with it on legal advice.

“Annulling the contract would have meant paying the company for the order without receiving the agreed materials, which are needed so that the Guardia Civil can fulfil its duties,” the sources said.

Despite the contract in question, they insisted the interior ministry shared the government’s commitment to not selling weapons to, or buying weapons from, Israel.

Childhood exposure to a toxin produced by bacteria in the bowel may be contributing to the rise of colorectal cancer in under-50s around the world, researchers say.

Countries, including some in Europe and Oceania, have witnessed an increase in young adults with bowel cancer in recent decades, with some of the steepest increases reported in England, New Zealand, Puerto Rico and Chile.

Doctors have pointed to soaring rates of obesity, widespread junk food and physical inactivity as potential drivers of the disease, but the new study finds that harmful strains of the common gut microbe E coli may be involved.

Prof Ludmil Alexandrov at the University of California, San Diego, said: “We think what we’re seeing is an infection in early life that subsequently increases one’s risk for developing colorectal cancer in the future.”

In an effort to understand the trend, an international team led by the University of California, San Diego analysed DNA from 981 colorectal tumours from patients in 11 countries in North America, South America, Asia and Europe. The majority of tumours were from older people, but 132 were early-onset bowel cancers.

The scientists found that hallmark genetic mutations caused by colibactin, a toxin secreted by some harmful strains of E coli, were more than three times as common in tumours removed from patients under the age of 40 than in those from patients over 70. The same signature mutations were also more common in countries with the highest rates of early-onset bowel cancer, according to the study, which has been published in Nature.

The patterns of mutations are thought to arise when children are exposed to colibactin before the age of 10. The mutations disrupt DNA in cells in the colon and may raise the risk of developing bowel cancer before the age of 50.

Global health records show bowel cancer rates increasing in adults under 50 in at least 27 countries, with incidence roughly doubling every decade for the past 20 years. If the trend continues, bowel cancer could become be the leading cause of cancer death in that age group by 2030.

The study does not prove that colibactin drives early-onset bowel cancer, but if harmful strains of E coli are involved, it raises further questions about how they arose, how children are exposed and whether interventions, such as probiotics, can replace the offending microbes. In the US and the UK, about 30 to 40% of children had colibactin-producing E coli in their bowels, Alexandrov said.

One possibility is that the harmful strains of E coli evolved and gained an advantage in the gut by producing colibactin. While the toxin damages the person’s DNA, it may help the microbes outcompete their neighbours. “This kind of microbial chemical warfare is quite common in evolution, where producing a toxin helps shape the niche or suppress microbial competitors,” Alexandrov said.

According to Cancer Research UK, which funded the research under the Cancer Grand Challenges partnership, more than half of bowel cancers are preventable, with a quarter linked to eating too little fibre, 13% linked to eating processed meat, 11% driven by obesity and 6% cause by alcohol. A further 5% are attributed to inactivity.

“Many early-onset colorectal cancer patients appear to have been exposed to a toxin, called colibactin, produced by some strains of the bacteria E coli in early life,” said Dr David Scott, the director of Cancer Grand Challenges at Cancer Research UK. “It’s unclear how the exposure originates, but we suspect that a combination of factors, including diet, may intersect during a crucial phase in the development of the gut microbiome.

“This study adds an important piece to the puzzle of early-onset cancers, but it isn’t conclusive, and more research will be needed to establish a definitive link between colibactin and an increased risk of early-onset colorectal cancer. Other Cancer Grand Challenges teams are looking deeper into the microbiome and other environmental factors to uncover what’s behind the global rise.”

Stock markets have risen around the world after Donald Trump said his tariffs on China would come down “substantially” and he had “no intention” of firing the chair of the US central bank, Jay Powell.

Weeks of tough talk on trade from White House officials have rattled investors and Trump now appears to be softening his tone. The president told reporters in Washington on Tuesday he planned to be “very nice” to China in trade talks and that tariffs could drop in both countries if they could reach a deal, adding: “It will come down substantially, but it won’t be zero.”

Overnight in Asia, Japan’s Nikkei rose by nearly 2%, Hong Kong’s Hang Seng was up 2.4% and the South Korean Kospi gained 1.6%.

The rally spread to Europe in early trading on Wednesday, with the UK’s FTSE 100 index up 1.6%, while the Italian FTSE MiB rose by 1.1%. Germany’s Dax gained 2.6% and France’s Cac 2.1%.

Meanwhile, US stocks opened on a high Wednesday morning, with the Dow rallying over 800 points, and the Nasdaq Composite up over 3%.

On Wednesday, the US treasury secretary, Scott Bessent, also took a softer, optimistic tone on China in remarks delivered at the Institute of International Finance in Washington DC, saying that China “knows it needs to change”.

“If China is serious on less dependence on export-led manufacturing growth and rebalancing toward a domestic economy … let’s rebalance together,” Bessent said. “This is an incredible opportunity.”

Bessent told investors in a private meeting on Tuesday that he expects a “de-escalation” of the trade war between China and the US in the “very near future”.

“‘America First’ does not mean America alone. To the contrary, it is a call for deeper collaboration and mutual respect among trade partners,” Bessent said on Wednesday.

Investor confidence also grew after Trump told reporters he would not fire Powell, the chair of the US Federal Reserve, reversing the previous day’s losses triggered by the president calling the central bank boss a “major loser”.

The president has criticised the Fed chair repeatedly for refusing to cut interest rates and last week hinted that he believed he could dismiss Powell before his term as the head of the central bank comes to an end in May next year.

Trump wrote on his social media platform, Truth Social, last week that Powell’s termination “could not come fast enough”, after the Fed chair raised concerns about the impact of trade tariffs on the American economy.

However, the suggestion from the White House that the US central bank will remain independent helped stocks to rise on Wednesday, as well as the prospect of lower tariffs on Chinese imports to the US.

The US dollar, which hit a three-year low on Tuesday before recovering, rose by 0.25% against a basket of major currencies.

Oil prices also rose on Wednesday, with Brent crude rising above $68 (£51) a barrel amid hopes that lower tariffs will be less damaging to the global economy. The rise was also led by new US sanctions targeting Iranian liquefied petroleum gas and the crude oil shipping magnate Seyed Asadoollah Emamjomeh.

Meanwhile, gold, which is traditionally viewed by investors as a safe haven asset during volatile periods, retreated from the new high of $3,500 (£2,620) an ounce it hit on Tuesday, to trade at about $3,307.

The world’s coral reefs have been pushed into “uncharted territory” by the worst global bleaching event on record that has now hit more than 80% of the planet’s reefs, scientists have warned.

Reefs in at least 82 countries and territories have been exposed to enough heat to turn corals white since the global event started in January 2023, the latest data from the US government’s Coral Reef Watch shows.

Coral reefs are known as the rainforests of the sea because of their high concentration of biodiversity that supports about a third of all marine species and a billion people.

But record high ocean temperatures have spread like an underwater wildfire over corals across the Pacific, Atlantic and Indian oceans, damaging and killing countless corals.

The 84% of reefs exposed to bleaching-level heat in this ongoing fourth event compares with 68% during the third event, which lasted from 2014 to 2017, 37% in 2010 and 21% in the first event in 1998.

Even reefs considered by scientists to be refuges from the ocean’s rising levels of heat have been bleached, Dr Derek Manzello, the director of Coral Reef Watch, said.

“The fact that so many reef areas have been impacted, including purported thermal refugia like Raja Ampat and the Gulf of Eilat, suggests that ocean warming has reached a level where there is no longer any safe harbour from coral bleaching and its ramifications,” he said.

Many areas have seen bleaching in back-to-back years, including the world’s biggest reef system, Australia’s Great Barrier Reef, where last week authorities declared a sixth widespread bleaching event in just nine years.

Australia’s other World Heritage-listed reef along the Ningaloo coast in Western Australia has seen its highest levels of heat stress on record in recent months.

Scientists on the other side of the Indian Ocean have reported bleaching in recent weeks affecting reefs off Madagascar and the east African coast, including South Africa’s World Heritage iSimangaliso wetland park.

Dr Britta Schaffelke, of the Australian Institute of Marine Science and coordinator of the Global Coral Reef Monitoring Network (GCRMN), said the event was unprecedented. “Reefs have not encountered this before.”

“With the ongoing bleaching it’s almost overwhelming the capacity of people to do the monitoring they need to do,” she said. “The fact that this most recent, global-scale coral bleaching event is still ongoing takes the world’s reefs into uncharted waters.

“[For] people who spend their entire working lives on monitoring and observing reefs and protecting reefs, and living alongside them and relying on them, seeing something like this must be devastating.

“Ecological grief is real. People who spend a lot of time under the water see it changing before their eyes,” she said.

The GCRMN is collating monitoring data for a status report due out next year, but Schaffelke said even that report would not give a full picture of the impact of the event.

Scientists in north and central America, including Florida, the Caribbean and Mexico, were among the first to raise the alarm after record ocean temperatures saw extreme bleaching in the northern hemisphere’s summer of 2023.

Corals can recover from bleaching if temperatures are not too extreme, but surveys done in the months after the event have begun to paint a picture of widespread coral death.

Across Florida, an average of one in five corals were lost. On the Pacific side of Mexico, one area lost between 50% and 93% of its corals. Almost a quarter of corals were killed by heat last year in the remote Chagos Islands in the middle of the Indian Ocean.

Scientists described a “graveyard of dead corals” in the northern section of the Great Barrier Reef after bleaching in early 2024 that caused 40% of corals to die in one area in the south.

After the extreme heat of 2023, Coral Reef Watch was forced to add three new threat levels to its global bleaching alert system to represent the unprecedented heat stress corals had faced.

Melanie McField, the founder of the Healthy Reefs for Healthy People initiative in the Caribbean, said reefs had fallen quiet across the world.

“Bleaching is always eerie – as if a silent snowfall has descended on the reef … there is usually an absence of fluttering fish and an absence of the vibrant colours on the reef,” she said. “It’s an ashen pallor and stillness in what should be a rowdy vibrant reefscape.”

Dr Lorenzo Álvarez-Filip, a coral scientist at the National Autonomous University of Mexico, has been surveying reefs across the Mexican Caribbean and the Gulf of Mexico after the bleaching in 2023 and again in 2024.

He said the most devastating impact was the loss of reef-building corals, such as elkhorns, that help protect coastlines and support a multitude of other marine life.

“Many of the coral colonies I knew well, and which had survived [a major disease] outbreak just a few years earlier, died in a matter of weeks.

“The feeling of impotence combined with the need to at least document what was happening made me very anxious – this was particularly hard when we were about to dive in sites where we knew there were big aggregations of susceptible corals. In almost all cases, we ended up with a very depressing feeling when we confirmed that all or nearly all the coral had died.”

Dr Valeria Pizarro, a senior coral scientist at the Perry Institute for Marine Science that works on reefs in the Bahamas and Caribbean, witnessed extreme bleaching in the Bahamas in July 2023.

She said “in a blink of my eyes” shallow reefs became white landscapes, with widespread death among staghorn corals used in restoration projects. Spectacular sea fans and soft corals died quickly.

“It was like they were melting with the heat,” she said.

“World leaders need to really commit to reduce fossil fuels and increase investments in clean energies and make it a reality. We need them to stop having it on paper and on the news, we need it to be real.”

Mark Zuckerberg’s Meta announced sweeping content moderation changes “hastily” and with no indication it had considered the human rights impact, the social media company’s oversight board has said.

The assessment of the changes came as the board also criticised the Facebook and Instagram owner for leaving up three posts containing anti-Muslim and anti-migrant content during riots in the UK last summer.

The oversight board raised concerns about the company’s announcement in January that it was removing factcheckers in the US, reducing “censorship” on its platforms and recommending more political content.

In its first official statement on the changes, the board – which issues binding decisions on removing Meta content – said the company had acted too quickly and should gauge the impact of its changes on human rights.

“Meta’s January 7, 2025, policy and enforcement changes were announced hastily, in a departure from regular procedure, with no public information shared as to what, if any, prior human rights due diligence the company performed,” said the board.

It urged Meta to live up to its commitment to uphold the United Nations’ principles on business and human rights, and urged the company to carry out due diligence on the impact.

“As these changes are being rolled out globally, the board emphasises it is now essential that Meta identifies and addresses adverse impacts on human rights that may result from them,” the statement said. “This should include assessing whether reducing its reliance on automated detection of policy violations could have uneven consequences globally, especially in countries experiencing current or recent crises, such as armed conflicts.”

The criticism of the changes was published alongside a series of content rulings including admonishment of Meta for leaving up three Facebook posts related to riots that broke out across the UK in the wake of the Southport attack on 29 July last year, in which three young girls were murdered. Axel Radukabana was jailed for a minimum of 52 years for carrying out the attack.

The board said the three posts, which contained a range of anti-Muslim sentiment, incited violence and showed support for the riots, “created the risk of likely and imminent harm” and should have been taken down. It added that Meta had been too slow to implement crisis measures as riots broke out across the UK.

The first post, which was eventually taken down by Meta, was text-only and called for mosques to be smashed as well as buildings where “migrants“ and “terrorists” lived to be set on fire. The second and third posts featured AI-generated images of a giant man in a union jack T-shirt chasing Muslim men, and of four Muslim men running after a crying blond toddler in front of the Houses of Parliament, with one of the men wielding a knife.

The board added that changes to Meta’s guidance in January meant users could now attribute behaviours to protected characteristic groups, for example, people defined by their religion, sex, ethnicity or sexuality, or based on someone’s immigration status. As a consequence, users can say a protected characteristic group “kill”, said the board.

It added that third-party factcheckers, which are still being used by Meta outside the US, had reduced the visibility of posts spreading a false name of the Southport attacker. It recommended the company research the effectiveness of community notes features – where users police content on platforms – which are also being deployed by Meta after the removal of US factcheckers.

“Meta activated the crisis policy protocol (CPP) in response to the riots and subsequently identified the UK as a high-risk location on August 6. These actions were too late. By this time, all three pieces of content had been posted,” the board said.

“The board is concerned about Meta being too slow to deploy crisis measures, noting this should have happened promptly to interrupt the amplification of harmful content.”

In response to the board’s ruling, a Meta spokesperson said: “We regularly seek input from experts outside of Meta, including the oversight board, and will act to comply with the board’s decision.

“In response to these events last summer, we immediately set up a dedicated taskforce that worked in real time to identify and remove thousands of pieces of content that broke our rules – including threats of violence and links to external sites being used to coordinate rioting.”

Meta said it would respond to the board’s wider recommendations within 60 days.

The board ruling also ordered the removal of two anti-immigrant posts in Poland and Germany for breaching Meta’s hateful conduct policy. It said Meta should identify how updates to its hateful content policy affect the rights of refugees and asylum seekers.

Levels of a little-known forever chemical known as TFA in European wines have risen “alarmingly” in recent decades, according to analysis, prompting fears that contamination will breach a planetary boundary.

Researchers from Pesticide Action Network Europe tested 49 bottles of commercial wine to see how TFA contamination in food and drink had progressed. They found levels of trifluoroacetic acid (TFA), a breakdown product of long-lasting Pfas chemicals that carries possible fertility risks, far above those previously measured in water.

Wines produced before 1988 showed no trace of TFA, the researchers found, but those after 2010 showed a steep rise in contamination. Organic and conventional wines showed a rise in TFA contamination, but levels in organic varieties tended to be lower.

“The wines that contained the highest concentration of TFA, on average, were also the wines we found with the highest amount of pesticide residue,” said Salomé Roynel from Pesticide Action Network Europe, which has called on the European Commission and EU member states to ban Pfas pesticides.

The researchers used 10 Austrian cellar wines from as early as 1974 – before policy changes they suspect led to the widespread use of precursor chemicals to TFA – as well as 16 wines bought in Austrian supermarkets from vintages between 2021 and 2024.

When the initial analysis revealed unexpectedly high levels of TFA contamination, they asked partners across Europe to contribute samples from their own countries.

The results from 10 European countries showed no detectable amounts of TFA in old wines; a “modest increase” in concentrations from 13 micrograms per litre to 21 between 1988 and 2010; and a “sharp rise” thereafter, reaching an average of 121 micrograms per litre in the most recent wines.

Pfas are chemicals that are widely used in consumer products, some of which have been shown to have harmful effects on people.

Authorities have historically not been troubled by potential health effects of TFA contamination, but recent studies in mammals have suggested it poses risks to reproductive health. Last year, the German chemical regulator proposed classifying TFA as toxic to reproduction at the European level.

A study in October argued the persistent nature of the substance and the growth in concentrations imply that TFA meets the criteria of a “planetary boundary threat for novel entities”, with increasing planetary-scale exposure that could have potential irreversible disruptive impacts on vital Earth system processes.

Hans Peter Arp, a researcher at Norwegian University of Science and Technology and lead author of the study, who was not involved in the Pesticide Action Network report, said that although the new research was only a preliminary screening, the results were “expected and shocking”.

“Overall they are consistent with what the scientific community knows about the alarming rise of TFA in essentially anything we can measure,” he said. “They also provide further evidence that Pfas-pesticides can be a major source of TFA in agricultural areas, alongside other sources such as refrigerants and pharmaceuticals.”

The main sources of TFA are thought to be fluorinated refrigerants known as F-gases, which disperse globally, and Pfas pesticides, which are concentrated in agricultural soil. Concentrations of F-gases rose after the 1987 Montreal protocol banned ozone-depleting substances such as chlorofluorocarbons, while Pfas pesticides are thought to have become widespread in Europe in the 1990s.

A study in November using field data from southern Germany revealed a “significant increase” in TFA groundwater concentrations when comparing farmland with other land uses.

Gabriel Sigmund, a researcher at Wageningen University in the Netherlands and co-author of the study, who was not involved in the Pesticide Action Network report, said TFA could not be degraded by natural processes and was very difficult and costly to remove during water treatment.

For most TFA precursor pesticides, there is little to no available data on their TFA formation rates, he added.

“This makes it very difficult to assess how much TFA formation and emission potential agricultural soils currently have, as accumulated pesticides can degrade and release TFA over time,” he said. “So even if we completely stopped the use of these pesticides now, we have to expect a further increase in TFA concentrations in our water resources and elsewhere over the next years.”