Israeli security forces have launched an operation in the West Bank city of Jenin, a day after bands of Israeli settlers attacked Palestinians, smashing cars and burning property and the new US president, Donald Trump, announced he was lifting sanctions on violent settlers.

At least six Palestinians were killed and 35 people were injured, according to the Palestinian health ministry

The Palestinian Red Crescent said its first responders treated seven people injured by live ammunition and that Israeli forces were hindering their access to the area.

The operation, codenamed “Iron Wall”, took place as the Gaza ceasefire entered a third day and was described by the Israeli prime minister, Benjamin Netanyahu, as an “another step towards achieving the goal we set – strengthening security in Judea and Samaria”. He said it included police, military and the Shin Bet internal intelligence agency.

“We act methodically and resolutely against the Iranian axis wherever it sends its arms – in Gaza, Lebanon, Syria, Yemen and Judea and Samaria,” Netanyahu added.

Jenin has been a focus of Israeli raids into the occupied West Bank throughout the 15-month war in Gaza. The Palestinian health ministry says more than 800 people have been killed in Israeli raids since Hamas’s 7 October 2023 attacks that triggered the war.

The Palestinian Authority, which administers parts of the West Bank, also launched its own raid into the area late last year while hoping to position itself as a serious player in governing postwar Gaza.

Sources quoted in the Israeli media said the operation was expected to last several days.

The Israeli government has accused Iran, which backs militant groups across the Middle East including Hamas in Gaza, of attempting to send weapons and money to militants in the West Bank.

Israeli settlers have set vehicles and properties on fire in the Palestinian villages where dozens of Palestinian prisoners released on Sunday exchange for three Israeli hostages handed over by Hamas to Israel were are returning. More than 21 Palestinians across the occupied West Bank have been inured as a result of the Israeli settlers’ attacks.

Jalal Bashir, the head of Jinasfut village council, was quoted as saying by Wafa news agency on Monday evening that the attacks took place in the villages of Jinasfut and Funduq, east of Qalqilya.

The Palestinian Authority has accused Trump of inciting Israeli settler violence after he on Monday rescinded sanctions imposed by the former Biden administration on far-right Israeli settler groups and individuals for allegedly committing violence against Palestinians.

The White House said Trump had rescinded an executive order issued on 1 February 2024, which authorised the imposition of certain sanctions “on persons undermining peace, security, and stability in the West Bank”.

Israel’s top general has resigned, citing the “terrible failure” of security and intelligence related to Hamas’s surprise attack on Israel on 7 October 2023 that triggered the war in Gaza.

Lt Gen Herzi Halevi, the chief of staff of the Israel Defense Forces (IDF), is the most senior Israeli figure to resign over the security breakdown when thousands of Hamas-led militants carried out a land, sea and air assault into southern Israel, rampaging through army bases and nearby communities for hours.

The Israeli opposition leader, Yair Lapid, said he saluted Halevi’s decision and also called on the prime minister, Benjamin Netanyahu, and his government to resign.

“Now, it is time for them to take responsibility and resign – the prime minister and his entire catastrophic government,” he said.

Halevi, who has been targeted for criticism by far-right members of Netanyahu’s governing coalition, will formally step down in March as the first stage of Israel’s ceasefire deal with Hamas in Gaza comes to an end.

He had been widely expected to resign and said he would complete the IDF’s own inquiries into the events of 7 October 2023. It was not immediately clear who would replace him.

Senior Israeli political figures, including Netanyahu, have resisted the establishment of a state commission of inquiry despite polling that suggests an overwhelming majority of Israelis back such a move.

Maj Gen Yaron Finkelman, the head of Israel’s Southern Command, which oversees operations in Gaza, also tendered his resignation on Tuesday.

Israeli political analysts have long suggested that Netanyahu planned to blame Halevi for the failures of 7 October. It is unclear whether Halevi will now back calls for a state inquiry.

In a statement shared with media, Halevi said the failures of 7 October would stay with him for the rest of his life. “On the morning of October 7, under my command, the IDF failed in its mission to protect Israel’s citizens,” he said.

“The state of Israel paid a heavy and painful price – in lives lost, in hostages taken, and in those wounded both physically and emotionally. The courageous acts of many – security forces personnel, IDF soldiers and commanders, and brave civilians – were not enough to prevent this great disaster.

“My responsibility for this terrible failure accompanies me every day, every hour and will remain with me for the rest of my life.”

Underlining Halevi’s unpopularity with the far right, Itamar Ben-Gvir, the leader of Jewish Power, who quit as national security minister over the ceasefire deal, welcomed Halevi’s resignation, insisting the next IDF chief must “defeat Hamas”.

About 1,200 people, mostly civilians, were killed in the attack and 250 were abducted. More than 90 of those taken captive are still in Gaza, about a third of whom are believed to be dead.

In his letter of resignation, Halevi said the military under his command had “failed in its mission to defend the state of Israel”. He said his resignation would take effect on 6 March, having begun what was meant to be a three-year term in January 2023.

Netanyahu said in a statement issued by his office that he had spoken to Halevi to thank him for his service, which had “led to great achievements” for Israel. The pair are expected to meet in the coming days.

Halevi was seen as being in broad agreement with the former defence minister Yoav Gallant, whom Netanyahu fired in November, but he appeared to be at odds with Gallant’s replacement, Israel Katz, over the direction of the war.

Halevi has indicated he believes Israel has accomplished most of its goals, while Katz has echoed Netanyahu’s vow to keep fighting until “total victory” over Hamas.

The far-right finance minister, Bezalel Smotrich, who has threatened to bring down Netanyahu’s government over the ceasefire deal, suggested on Monday that the IDF needed a new chief of staff. He told Army Radio that Israel would not be able to win in Gaza with Halevi at the helm.

“We need to occupy the strip and establish a military government there. I want a chief of staff who understands that this is his goal, stands behind it and is going to realise it,” he said.

Hamas has said four more female Israeli hostages will be freed this weekend in return for Palestinian prisoners, as the new US president, Donald Trump, said he was not confident that the ceasefire deal that he personally insisted on would hold.

The next group of hostages due to be released is expected to include captured female Israeli soldiers, who will be exchanged for Palestinian prisoners serving more lengthy sentences who are being held in Israeli jails, some of whom will be deported to third countries.

With the release of three women on Sunday, seven Israeli women remain on the list of the initial group of 33 hostages designated for release in the first phase of the three-part ceasefire agreement, which includes women, children, elderly and sick people.

Five of those remaining women are soldiers who were captured on 7 October 2023 during Hamas’s surprise attack on southern Israeli communities close to the Gaza border.

Although Hamas has not notified mediators in Qatar of the names of hostages to be released, the speculation in the Israeli media is that it will include one civilian and three IDF spotters captured in Nahal Oz.

The arrangements for the release are expected to be largely similar to last week with Hamas delivering hostages to the Red Cross to be conveyed to Israeli forces still in Gaza and then Palestinian prisoners being released from jail hours later.

The Hamas statement came as David Barnea, head of the Mossad, Israel’s foreign intelligence organisation; and Ronen Bar, the head of the domestic security agency, the Shin Bet; visited Cairo on Monday, to meet Egyptian intelligence officials to discuss how Palestinian prisoners would be deported as part of the deal.

Israel holds more than 10,300 Palestinian prisoners, while an estimated 96 Israelis are still being held in Gaza after Sunday’s release of three women, including the joint Israeli-British citizen Emily Damari, in exchange for 90 Palestinian prisoners, most of whom were women and children.

In a statement released by Nader Fakhouri, of Hamas’s martyrs, injured, and prisoners office, he confirmed “the second part of the first phase of the Palestinian resistance factions’ agreement with the Israeli occupation will begin on Saturday 25 January” although the handover itself is not expected until Sunday.

Under the ceasefire deal, any female Israeli soldier released would mean the release of 30 Palestinian prisoners serving life sentences and 20 with high-term sentences.

Trump’s comment that he was not confident the deal would hold came during the signing of a tranche of executive orders after his inauguration on Monday, and added further fuel to concerns over the fragility of the complex deal that requires further negotiations on ever-more difficult issues as the ceasefire progresses.

Trump’s remarks are doubly worrying as he is in effect one of the guarantors of the ceasefire, having intervened personally in the closing days of Joe Biden’s presidency to insist to the Israeli prime minister, Benjamin Netanyahu, that a ceasefire must happen.

“It’s not our war, it’s their war,” Trump said. “But I’m not confident. But I think they’re very weakened on the other side.”

Trump comments came as he revoked a key Biden-era decision that had been seen as a source of pressure on Israel, the sanctioning of Israelis seen as being involved in violent settler activity.

Trump made his comments as an Israeli military spokesperson said Palestinians in Gaza would be formally permitted to return to the north of the coastal territory in about a week if Hamas upheld all the terms of the deal, although many have already visited.

Emergency services in the Gaza Strip report that the remains of 50 bodies were found near the southern Gaza city of Khan Younis and transferred to Nasser hospital in the city.

The statement added that dozens of bodies were also located on Monday in Rafah in the southern part of the territory.

According to the Hamas-run Gaza information office, at least 11,000 people are still missing.

The latest developments came as the first details of conditions in which the three women released on Sunday were kept.

According to a report on Israel N12 television channel, Doron Steinbrecher, Romi Gonen, and Emily Damari were held together at first but later separated, both in tunnels underground and at locations above ground, moving dozens of times, with at least one of the women saying in her testimony she believed she would die in Gaza.

They also appear to have had access to television at times, saying they were aware of their families campaign for their release.

“We saw your fight; we heard our families battling for us,” they said.

A hotel fire at a popular ski resort in north-west Turkey on Tuesday has killed at least 66 people, Turkey’s interior minister said.

Ali Yerlikaya said at least 51 other people had been injured.

“We are in deep pain. We have unfortunately lost 66 lives in the fire that broke out at this hotel,” Yerlikaya told reporters after inspecting the site.

The health minister, Kemal Memişoğlu, said at least one of the injured was in serious condition.

The fire broke out at about 3.30am in the restaurant of the 12-storey Grand Kartal hotel in the resort of Kartalkaya in Bolu province, officials and reports said. The cause of the fire is under investigation.

Two of the victims died after jumping from the building in a panic, Bolu’s governor, Abdulaziz Aydin, told the state-run Anadolu Agency. NTV television said some people tried to climb down from their rooms using sheets and blankets.

There were 234 guests staying at the hotel, Aydin said.

Necmi Kepcetutan, a ski instructor at the hotel, said he was asleep when the fire started and he rushed out of the building. He told NTV television that he then helped about 20 guests out of the hotel.

He said the hotel was engulfed in smoke, making it difficult for guests to locate the fire escape. “I cannot reach some of my students. I hope they are OK,” he said.

Television images showed the roof and top floors of the hotel on fire.

Witnesses and reports said the hotel’s fire detection system failed to operate. “My wife smelled the burning. The alarm did not go off,” Atakan Yelkovan, a guest staying on the third floor of the hotel, told the IHA news agency.

“We tried to go upstairs but couldn’t, there were flames. We went downstairs and came here [outside],” he said.

Yelkovan said it took about an hour for firefighters to arrive. “People on the upper floors were screaming. They hung down sheets … some tried to jump,” he said.

The government has appointed six prosecutors to lead an investigation into the fire. NTV television suggested that the wooden cladding on the exterior of the hotel, in a chalet-style design, may have accelerated the spread.

The 161-room hotel is on the side of a cliff, hampering efforts to combat the flames, the station reported.

NTV showed a smoke-blackened lobby, its glass entrance and windows smashed, its wooden reception desk charred and a chandelier on the ground.

Kartalkaya is a popular ski resort in the Köroğlu mountains, about 185 miles (300km) east of Istanbul. The fire happened during the school semester break when hotels in the region are busy.

Aydin’s office said 30 fire trucks and 28 ambulances were sent to the site.

Other hotels at the resort were evacuated as a precaution and guests were placed in hotels around Bolu.

Meanwhile, a gas explosion at a hotel at another ski resort in central Turkey injured four people.

The explosion took place at the Yildiz Mountain Winter Sports Center in Sivas province. Two skiers and their instructor were slightly injured while another instructor suffered second-degree burns on the hands and face, the Sivas governor’s office said.

People in Kyiv expressed a mixture of hope and scepticism on Tuesday that Donald Trump can end the war in Ukraine, as Volodymyr Zelenskyy praised the US president as a “decisive” leader who would bring about a “just peace”.

Trump described himself as a “peacekeeper” who would avoid entangling the US in damaging foreign wars in his inauguration speech, but did not mention Ukraine, or explain how he might persuade Vladimir Putin to engage in negotiations almost three years after his full-scale invasion.

Speaking later to reporters in the White House, Trump claimed 1 million Russian soldiers had died in the war and suggested that it was in the interests of both sides to stop fighting. “He [Putin] is destroying Russia. He should make a deal. Zelenskyy wants to make a deal,” Trump said.

Ukrainians outside Lukianivska metro station in Kyiv the next morning – where a Russian missile killed three people on Saturday – said they were anxiously waiting to see what happened next. Behind them was the wrecked facade of an office building and a damaged branch of McDonald’s, the first in the Ukrainian capital.

“I think a deal is unrealistic. Trump is blah blah blah,” Valeriia, a 23-year-old shop worker, said. “He promised to end the conflict in 24 hours. That won’t happen. My friends are split 50-50 between those who think he can do something, and those who don’t.”

“I watched the inauguration on TV. Trump impressed me. We need to stop the war,” Mykola, a retired physicist, said. He said he used to live in New York and had seen Trump several times outside Trump Tower. “I think he can really do something. He’s made a ceasefire in Israel and Gaza.”

The scientist suggested freezing the current frontline while diplomatic negotiations began. It is unclear if Zelenskyy would agree to such a plan, or agree to probable Russian demands including Ukraine not joining Nato and the loss of further territory. “We have to reach an agreement. It doesn’t matter how,” Mykola said.

Zelenskyy has welcomed Trump’s return to the White House and congratulated him on Monday. “The peace through strength policy he announced provides an opportunity to strengthen American leadership and achieve a long-term and just peace,” Zelenskyy wrote. Ukraine looked forward to “mutually beneficial cooperation”.

His enthusiastic comments came after strained relations between Kyiv and the Biden administration. Ukrainian officials said the former president pursued an overcautious policy of crisis management, with military aid sent too late and in insufficient quantities to defeat Russia. US officials, meanwhile, dismissed Zelenskyy as unrealistic.

There is no sign yet that Zelenskyy’s diplomatic overtures to Trump are reciprocated. “I think Trump doesn’t want him. He didn’t invite Zelenskyy to the inauguration,” Anna Fedorivna, an English-speaking graduate, said. “Maybe Trump can find a way forward. He talks to Putin at least, which Biden didn’t. I hope something positive can emerge.”

The Ukrainian journalist Kristina Berdynskykh watched Trump’s speech in a smoke-filled bar in downtown Kyiv. “There was nothing in it about Ukraine. The only foreign policy to come up was Panama, Mexico and Mars,” she said. “I think Trump doesn’t think about Ukraine a lot. Our main challenge in the future will be to keep his attention.”

Berdynskykh said Trump’s promise to increase US oil and gas drilling was good news for Ukraine. It would push down the price of Russian oil, sent around the world in a shadow fleet, and used by the Kremlin to fund its massive war economy. “I don’t think Trump will give Putin Ukraine as a present. That would make America look weak,” she said.

Anton Herashchenko, a commentator and former government adviser, said Trump wanted to the war to end quickly and for Ukraine to become Europe’s “internal” problem. The US president’s main interests were elsewhere – in the American continent and Asia-Pacific, he said. “As of today, the situation of strategic uncertainty continues,” he said.

Trump’s special envoy on Ukraine, Keith Kellogg, has suggested that the two sides could reach an agreement in 100 days. Kellogg, however, cancelled a trip to Kyiv scheduled for early January. Few Ukrainians believe this timetable is realistic. More likely, they think, is that Trump will end US military assistance to Ukraine, seeing it as an unwanted Biden legacy.

In Moscow, Putin has shown no willingness to compromise. His demands include the annexation of four Ukrainian regions, including areas he does not control, and the replacement of Zelenskyy’s government with a “neutral” pro-Russian administration. On the battlefield, meanwhile, Russian forces are advancing at their quickest rate since 2022.

“I don’t think Putin will stop until he has destroyed Ukraine. He’s a fool,” Petro Hryhorovych, a pensioner, said, adding that an explosion on Saturday woke him at 6am, shaking his flat. He added: “Even so, there is a little bit of hope. I want the war to finish. So many peaceful people have died.”

Antibiotics, antivirals and vaccines could be used to tackle dementia, according to experts, who say repurposing drugs approved for other conditions could dramatically speed up the hunt for a cure.

The number of people living with the disease globally is forecast to almost triple to 153 million by 2050, presenting a major threat to health and social care systems.

New drugs are coming down the pipeline, but slowly, and experts say more must be done to see whether existing medicines could help prevent or treat dementia.

Dr Ben Underwood, from the University of Cambridge, said: “We urgently need new treatments to slow the progress of dementia, if not to prevent it. If we can find drugs that are already licensed for other conditions, then we can get them into trials and – crucially – may be able to make them available to patients much, much faster than we could do for an entirely new drug.”

In new research led by Cambridge and the University of Exeter, researchers examined studies which linked commonly used drugs to dementia risk. They analysed data from 14 studies that tracked the health of more than 130 million people and involved 1m cases of dementia. They also analysed prescription data and identified several drugs that appeared to be linked to dementia risk.

Overall, they found a “lack of consistency” between studies in identifying drugs that might modify a person’s risk of dementia. But they found some “candidates” that could warrant further studies.

One unexpected finding was an association between antibiotics, antivirals and vaccines and a reduced risk of dementia. The finding supports the hypothesis that some cases of the disease may be triggered by viral or bacterial infections.

Anti-inflammatory drugs such as ibuprofen were also found to be associated with reduced risk. Inflammation is increasingly being seen to be a significant contributor to a wide range of diseases.

There was conflicting evidence for several classes of drugs, with some blood pressure medications and antidepressants and, to a lesser extent, diabetes medication associated with a decreased risk of dementia and others associated with increased risk, the researchers said.

But the study published in journal Alzheimer’s and Dementia: Translational Research and Clinical Interventions suggests there is “biological plausibility” for some medicines to be tested further.

“The association between antibiotics, antivirals and vaccines and decreased risk of dementia is intriguing,” the researchers wrote. “Viral and bacterial infectious causes of common dementias have been proposed, supported by epidemiological data linking infection to dementia risk, antiviral drugs have been identified as some of the most promising repurposed drugs for dementia and there is increasing interest in vaccination as being generally protective.

“Our findings support these hypotheses and lend further weight to these agents as being potentially disease-modifying or preventive for dementia.”

Dr Julia Dudley, the head of research strategy at Alzheimer’s Research UK, said it was too early to say if the existing drugs could be used to reduce the risk of dementia. Researchers will need to confirm the findings in clinical trials, she added.

Dr Richard Oakley, associate director of research and innovation at the Alzheimer’s Society, said: “If we can repurpose drugs that have already been shown to be safe and approved for use for other conditions, this could save millions of pounds and decades it takes to develop a new dementia drug from scratch, and get us closer to beating dementia.

“This research provides some initial groundwork and indicates which drugs have potential for being repurposed for dementia and should be prioritised for further investigation.”

A third of the Arctic’s tundra, forests and wetlands have become a source of carbon emissions, a new study has found, as global heating ends thousands of years of carbon storage in parts of the frozen north.

For millennia, Arctic land ecosystems have acted as a deep-freeze for the planet’s carbon, holding vast amounts of potential emissions in the permafrost. But ecosystems in the region are increasingly becoming a contributor to global heating as they release more CO₂ into the atmosphere with rising temperatures, a new study published in Nature Climate Change concluded.

More than 30% of the region was a net source of CO₂, according to the analysis, rising to 40% when emissions from wildfires were included. By using monitoring data from 200 study sites between 1990 and 2020, the research demonstrates how the Arctic’s boreal forests, wetlands and tundra are being transformed by rapid warming.

“It is the first time that we’re seeing this shift at such a large scale, cumulatively across all of the tundra. That’s a pretty big deal,” said Sue Natali, a co-author and lead researcher on the study at the Woodwell Climate Research Center.

The shift is occurring despite the Arctic becoming greener. “One place where I work in interior Alaska, when the permafrost thaws, the plants grow more so you can sometimes can get an uptick in carbon storage,” Natali said. “But the permafrost continues to melt and the microbes take over. You have this really big pool of carbon in the ground and you see things like ground collapse. You can visually see the changes in the landscape,” she said.

The study comes amid growing concern from scientists about the natural processes that regulate the Earth’s climate, which are themselves being affected by rising temperatures. Together, the planet’s oceans, forests, soils and other natural carbon sinks absorb about half of all human emissions, but there are signs that these sinks are under strain.

The Arctic ecosystem, spanning Siberia, Alaska, the Nordic countries and Canada, has been accumulating carbon for thousands of years, helping cool the Earth’s atmosphere. In a warming world, the researchers say that the carbon cycle in the region is beginning to change and needs better monitoring.

Anna Virkkala, the lead author of the study, said: “There is a load of carbon in the Arctic soils. It’s close to half of the Earth’s soil carbon pool. That’s much more than there is in the atmosphere. There’s a huge potential reservoir that should ideally stay in the ground.

“As temperatures get warmer, soils get warmer. In the permafrost, most of the soils have been entirely frozen throughout the full year. But now the temperatures are warmer, there’s more organic matter available for decomposition, and carbon gets released into the atmosphere. This is the permafrost-carbon feedback, which is the key driver here.”

Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield in the Guardian app for more nature coverage

A third of the Arctic’s tundra, forests and wetlands have become a source of carbon emissions, a new study has found, as global heating ends thousands of years of carbon storage in parts of the frozen north.

For millennia, Arctic land ecosystems have acted as a deep-freeze for the planet’s carbon, holding vast amounts of potential emissions in the permafrost. But ecosystems in the region are increasingly becoming a contributor to global heating as they release more CO₂ into the atmosphere with rising temperatures, a new study published in Nature Climate Change concluded.

More than 30% of the region was a net source of CO₂, according to the analysis, rising to 40% when emissions from wildfires were included. By using monitoring data from 200 study sites between 1990 and 2020, the research demonstrates how the Arctic’s boreal forests, wetlands and tundra are being transformed by rapid warming.

“It is the first time that we’re seeing this shift at such a large scale, cumulatively across all of the tundra. That’s a pretty big deal,” said Sue Natali, a co-author and lead researcher on the study at the Woodwell Climate Research Center.

The shift is occurring despite the Arctic becoming greener. “One place where I work in interior Alaska, when the permafrost thaws, the plants grow more so you can sometimes can get an uptick in carbon storage,” Natali said. “But the permafrost continues to melt and the microbes take over. You have this really big pool of carbon in the ground and you see things like ground collapse. You can visually see the changes in the landscape,” she said.

The study comes amid growing concern from scientists about the natural processes that regulate the Earth’s climate, which are themselves being affected by rising temperatures. Together, the planet’s oceans, forests, soils and other natural carbon sinks absorb about half of all human emissions, but there are signs that these sinks are under strain.

The Arctic ecosystem, spanning Siberia, Alaska, the Nordic countries and Canada, has been accumulating carbon for thousands of years, helping cool the Earth’s atmosphere. In a warming world, the researchers say that the carbon cycle in the region is beginning to change and needs better monitoring.

Anna Virkkala, the lead author of the study, said: “There is a load of carbon in the Arctic soils. It’s close to half of the Earth’s soil carbon pool. That’s much more than there is in the atmosphere. There’s a huge potential reservoir that should ideally stay in the ground.

“As temperatures get warmer, soils get warmer. In the permafrost, most of the soils have been entirely frozen throughout the full year. But now the temperatures are warmer, there’s more organic matter available for decomposition, and carbon gets released into the atmosphere. This is the permafrost-carbon feedback, which is the key driver here.”

Find more age of extinction coverage here, and follow the biodiversity reporters Phoebe Weston and Patrick Greenfield in the Guardian app for more nature coverage

The west should seize the opportunity to target the Tehran-backed Houthi leadership in Yemen while the Iranian government is weakened, the vice-president of the UN-backed government in Aden has said.

Aidarus al-Zoubaidi said that Iran’s reverses in Lebanon, Syria and Gaza had left the country “massively weakened”. “They have one remaining domain and that is Yemen,” Zoubaidi told the Guardian. “Now is the time to counter the Houthis and push them back into their position.”

He said Yemen ground forces should work in cooperation with western airstrikes as part of a multi-pronged strategy.

Speaking from the World Economic Forum in Davos, he also called on the new US administration to designate the Houthis a foreign terrorist organisation, and praised Donald Trump for showing “decisive leadership”.

His remarks suggest that the Presidential Leadership Council, based in the Yemeni city Aden, regards the weakening of Iran and the return of Trump as an opportunity to launch a joint military offensive against the Houthis, including the potential use of ground forces.

He predicted: “Iran will not give up on the Houthis, but on the contrary double down on its support for the Houthis as the last remaining component of its chain of proxy forces. So this is the right time for us also to double time and push them to the maximum”. Iran says the Houthis are an independent political force.

Zoubaidi said the Aden government was willing to provide intelligence advice to all those mounting attacks on Houthi positions. “We are willing to work with everyone on this”, he said, in remarks that suggest some cooperation could take place even with Israel.

He said the attacks mounted so far largely by the US and the UK on the Houthis “had not been effective because it’s not targeting the Houthi leadership, or their main locations or headquarters. It’s not joined-up, or comprehensive. It’s just airstrikes. Joined-up means also a military operation on the ground”.

The US attacks have been designed to deter the Houthis from firing on commercial shipping in the Red Sea, attacks the Houthis say have been acts of solidarity with Palestinians in Gaza. The group gained control of the capital of Yemen, Sana’a, in 2014.

The Houthi leader, Abdul-Malik al-Houthi, said on Monday that during the Gaza ceasefire, Houthi forces would only attack shipping directly linked to Israel, meaning British- or US-owned ships would be spared. The Houthis say they are in talks to release the crew of the Galaxy Leader, who have been held hostage by the group since November 2023.

Zoubaidi said the social structure of Houthi support was different from that of Hezbollah and Hamas, so simply going after its leadership would not be enough.

He also criticised the Biden administration for “a lack of assertiveness”, highlighting the decision to lift the foreign terrorist designation in favour of a lesser classification. Zoubaidi, who is also the president of the separatist Southern Transitional Council (STC), said “the decision had given the Houthis space in which to work and to do what they have done”.

Overall his remarks were a sign that the year-old diplomatic roadmap for peace was no longer seen as a viable option.

The STC enjoys support from the United Arab Emirates, and it is not clear whether Zoubaidi’s call for a tougher military approach has the support of Saudi Arabia or the new US foreign policy team.

Dozens of Indonesian schoolchildren have suffered food poisoning after consuming free meals offered through a new flagship program of President Prabowo Subianto, his office has confirmed.

Rolled out this month, Prabowo’s multi-billion dollar policy was a centrepiece of the former general’s election campaign, with a pledge to reach 82.9 million children and pregnant women out of the country’s population of 280 million by 2029.

Prabowo has said the program will improve their quality of life and boost economic growth.

But aside from the financial challenges and Herculean logistical effort required, the government is facing another issue with 40 students from a school in Sukoharjo, Central Java vomiting and feeling nauseous after consuming the meals in recent days.

“There was an incident,” Indonesia’s presidential spokesperson Hasan Nasbi confirmed to the Guardian, “Forty children who ate marinated chicken experienced nausea and vomiting.”

The affected students has been treated and medicated and their conditions improved, he said. The food had been immediately withdrawn and the “undesirable incident” would be used as a “very important evaluation” to ensure food safety going forward, he said.

Reports in the Indonesian media said the food poisoning in the Central Java school was not an isolated incident, claiming that dozens of students had also fallen ill after eating government-provided free meals in Nunukan, North Kalimantan.

Nasbi did not immediately comment on those reports.

The program, intended to reduce stunting and malnutrition, has a projected cost of $45bn over five years, with reports that an additional $6.11bn will be needed to expand it to reach more than a quarter of its population by year-end.

Stunting affects 21.5% of children in the world’s largest archipelago, and is more pronounced in the country’s less developed eastern regions.

This month at least 190 kitchens run by third-party catering services opened nationwide, including some run by military bases, with officials aiming to feed 570,000 on the opening day.

As he approaches the 100th day of his presidency, Prabowo’s populist policies have earned him a high approval rating, with a survey by Litbang Kompas released on Monday finding that 80.9% approved of the new government’s performance so far.

The Russian president, Vladimir Putin, held a video call with his Chinese counterpart, Xi Jinping, in a symbolic display of unity just hours after Donald Trump was sworn in as the 47th president of the US.

Speaking from his Novo-Ogaryovo residence outside Moscow, Putin highlighted the close ties between the two countries, stating that their relations were based on “shared interests, equality, and mutual benefit“, calling Xi his “dear friend”.

Moscow has grown increasingly reliant on China as a trade partner and a crucial diplomatic ally amid its escalating conflict with the west after launching a full-scale invasion of Ukraine nearly three years ago. In turn, Beijing has capitalised on Russia’s isolation from the west to secure preferential access to its resources and markets.

The two countries declared a “no-limits” partnership in February 2022 when Putin visited Beijing just days before he sent tens of thousands of troops into Ukraine. The two leaders have since then frequently visited each other’s capitals and have become indispensable allies in their shared goal of reshaping the global order in opposition to the west.

Although neither leader directly mentioned Trump in the televised segment of their call, the timing of their conversation may indicate that Putin and Xi are hoping to coordinate their approach to engaging with the new US administration.

Trump has threatened to impose tariffs and other measures against China in his second term, while he has also hinted at ways the two rival powers could cooperate on issues such as regional conflicts and curbing the export of substances used in the production of fentanyl.

Trump has vowed to swiftly end the war in Ukraine, a move that will probably involve China, given Russia’s growing dependence on Beijing.

There was no official readout from the Putin-Xi call, but the Kremlin foreign policy aide Yuri Ushakov stated that they discussed talks with Trump and the prospects for a potential peace deal to end the war in Ukraine. Ushakov added that Moscow was “ready for serious dialogue” with the Trump administration over Ukraine and was awaiting concrete proposals that could serve as the foundation for talks between the leaders.

Ushakov’s remarks were the latest in a series of comments from Russian officials indicating their willingness to discuss the war in Ukraine with Trump, although a clear path to peace remains elusive.

Putin, who is yet to talk to Trump, congratulated him on taking office on Monday in televised remarks during a video call with officials and welcomed his intention to open a dialogue with Moscow.

Asked about the war in Ukraine shortly after his inauguration, Trump said he would meet Putin “very soon” and that his Russian counterpart was “destroying Russia” by refusing to negotiate a ceasefire with Ukraine.

Trump also told reporters that the Ukrainian president, Volodymyr Zelenskyy, had told him he wanted to make a peace deal and voiced hope that Putin would follow suit. “I think Russia is in big trouble,” Trump said, claiming that 1 million Russian soldiers had died in the war in Ukraine and saying the conflict was taking a severe toll on the Russian economy.

Financial markets shrugged after Donald Trump outlined plans to impose punitive tariffs on Mexico and Canada as soon as next month while signing scores of executive orders on his first day in office.

The US president told reporters in the White House’s Oval Office he was thinking about introducing 25% US tariffs on imports from Mexico and Canada as soon as 1 February.

Wall Street was largely unmoved as it opened for trading for the first time after the inauguration, with the benchmark S&P 500 rising just 0.4% on Tuesday morning. The technology-focused Nasdaq Composite was flat.

The US dollar, which had initially fallen in the hours after Trump took office, reversed course after the comments to hit five-year highs against the Canadian dollar, and rose by 1% against the Mexican peso.

But stock markets, which rallied in the aftermath of Trump’s election victory in November, were largely calm in reaction to his return to the White House. US markets were closed for Martin Luther King Jr Day on Monday, so Asian markets were the first to respond. Japan’s Nikkei index swung between losses and gains and ended the day 0.3% higher.

Other Asian markets also made modest gains, with Hong Kong’s Hang Seng climbing by nearly 1% and China’s Shenzhen market rising by 0.5%, while the Shanghai and South Korean exchanges were slightly in the red and the Indian market lost nearly 0.6%.

In Europe, the UK’s FTSE 100 index edged just four points higher to 8,524 by mid-morning. Germany’s Dax and Italy’s FTSE MIB slipped slightly, while France’s CAC rose by 0.25%. The pound and the euro lost about 0.6% against the dollar. Sterling had risen by 1.3% on Monday, its biggest daily jump since November 2023.

US stock futures pointed to modest gains on Wall Street when markets open for trading at 2.30pm GMT.

Oil prices tumbled, with Brent crude losing more than $1 a barrel to fall to $79.10 a barrel, while West Texas Intermediate fell by $1.73 a barrel to $76.15 a barrel. Gold – seen as a safe haven asset – was back in favour, hitting a two-month high amid uncertainty over US tariffs.

“Once again, Trump appears to care little for who are perceived to be allies or foes, with Canadian and Mexican currencies hit hard … So much for the plan to raise tariffs by 2% a month,” said Joshua Mahony, an analyst at Scope Markets.

“However, the Chinese markets clearly felt more optimistic, with Trump’s decision to reinstate TikTok followed up by a lack of any mention around tariffs on Chinese imports. For now anyway.”

Investors are also keeping an eye on the World Economic Forum in the Swiss ski resort of Davos, where the world’s political and business leaders are gathered for their annual meeting. They include Ding Xuexiang, the vice-premier of China, where there may be relief that Trump has not fleshed out his plans for taxing Chinese imports.

On Monday, Trump said he wanted to reverse the US trade deficit with the EU through tariffs or more US energy exports.

European natural gas prices fluctuated, after he lifted a moratorium on new export licences, easing uncertainty over longer-term global supply. Dutch month-ahead futures, Europe’s gas benchmark, traded 0.3% higher at €48 a megawatt-hour in Amsterdam.

The US president also repeated a call for the EU to buy more American oil and gas if the bloc wants to avoid tariffs. The US is already Europe’s biggest supplier of liquefied natural gas.

“More oil production, no indication of crypto mining, punitive tariffs against Mexico and Canada: these are the three key points for investors from Trump’s inaugural address,” said Jochen Stanzl, the chief market analyst at CMC Markets. Brent crude futures were flat at $80.1 a barrel.

“We can only hope that Trump will spare the EU and Germany from punitive tariffs until after the German parliamentary elections, as the outgoing government will hardly be in a position to react to changes in trade relations with the US. However, this reprieve should not be taken as permanent. Sooner or later, Trump will also target Germany.”

Bitcoin, which rose by 4% on Monday to reach a fresh record high above $109,000 on hopes of a crypto-friendly administration, has retreated since then.

Stanzl said: “There were probably one or two investors who had hoped for more. It seems that Trump is prioritising issues other than supporting the crypto industry. But one thing is clear: a positive word from Trump and bitcoin could rise significantly again. Investors are just waiting for it.”

At the end of another breathless exchange in the early stages of the most highly anticipated match of the Australian Open, alone in the centre of the colossal Rod Laver Arena, Novak Djokovic squatted down on to the court before solemnly stretching his lower body.

In the previous 30 seconds, Djokovic had been run ragged by a Carlos Alcaraz in full flight; he was ruthlessly dragged from sideline to sideline by the Spaniard’s nuclear groundstrokes, pulled forward by a delicate drop shot and then vanquished by a laser-like forehand winner as he stood helplessly at the net. Djokovic pulled up from the gruelling point limping and he called for the physio.

It seemed for a few fleeting moments that the challenge of holding off one of the most special young players in history might be beyond Djokovic and his worn-down 37-year-old body. Instead, he responded with a masterpiece of a performance in the tournament that has defined his career, offering yet another reminder of his greatness by rallying from a set down to defeat Alcaraz 4-6, 6-4, 6-3, 6-4.

Djokovic has now reached 50 grand-slam semi-finals, extending his all-time record. As he continues to rewrite all the age-based records in his name – he is now the third man to reach multiple grand slam semi-finals after turning 37 and he is also the third man in the Open era to reach the semi-finals at this age. Ken Rosewall and Roger Federer are the others to achieve this distinction.

In his 12th Australian Open semi-final Djokovic, the seventh seed, will face the third seed, Alexander Zverev, who defeated the 12th seed, Tommy Paul, 7-6 (1), 7-6 (0), 2-6, 6-1.

With 16 years separating Djokovic and Alcaraz, their contests over the past two years have illustrated the changing complexions of their careers. While their first meeting occurred when Djokovic was No 1 and Alcaraz had only just broken into the top 10, Alcaraz is now an established four-time grand-slam champion and, as the third seed, this was his section of the draw. Djokovic entered the match a clear challenger and underdog as he tried hard to hold off Alcaraz.

The last time they met, Djokovic provided perhaps the most spectacular illustration of his mental strength and desire in his career as he willed himself to the Olympic gold medal in Paris in two incredibly tight sets. Outperforming the new generation over the best of five sets format at the grand slams, however, becomes more difficult each year.

In the strong winds on a cool night , the conditions did not stop the players from trading blows with immaculate depth and intensity from early on. After a slow start, though, it was Alcaraz who dictated and decided most exchanges in the first set with his forehand and determination to close down the net.

At 4-4 on Djokovic’s serve, the Serb pulled up badly at the end of a gruelling rally. After stretching out his lower body, Djokovic spent the rest of the game limping and he took an off-court medical timeout after conceding the break. Once the match restarted, Alcaraz coolly served out the set.

His left thigh bandaged tightly, Djokovic spent much of the second set limping between points, wincing after sharp movements and he appeared to be in genuine pain. But he also played with astonishing focus and commitment, forcing himself inside the baseline and playing fearless attacking tennis as he pounded his forehand without hesitation. Even as Alcaraz retrieved his early break, testing Djokovic’s movement with ample drop shots and sustained aggression, Djokovic maintained his composure. He made his move at 5-4 on Alcaraz’s serve, ending an immaculate return game with a searing backhand return winner to level the match.

In his discomfort, Djokovic presented the sharpest version of himself. He was relentless, deflecting almost every return with consistency and depth, pinning Alcaraz in his backhand corner and finding the answer to so many of the long exchanges with his forehand aggression. Alcaraz, meanwhile, was too passive and flat, unable to strike the ball with unrelenting freedom and aggression.

But Alcaraz fought to the bitter end. Down a break point at 2-4, he somehow pulled himself through an utterly brutal 33-stroke rally that left both players hunched over in exhaustion. After holding serve, Alcaraz used the desperate encouragement from the delirious crowd to generate two break points. But Djokovic was not to be denied as he sealed another supreme achievement in a 20-year grand slam career filled with them.

After closing out a monumental victory with a steely hold, Djokovic shared a warm, pointed embrace with his new coach, Andy Murray. It was precisely for these moments, the biggest matches against the best players, that Djokovic enlisted his old rival to his cause.

This was a reflection of his enduring commitment to his craft and the incredible level he continues to compete at so deep in his career, but also of the work they have produced in a short amount of time. As he chases down his 25th grand slam title, it has only just begun.