Sudanese military forces recaptured the presidential palace early Friday in the battle-scarred capital, Khartoum, signaling a potential turning point in Sudan’s devastating civil war, now approaching its third year.

Videos and photos showed soldiers standing triumphantly at the entrance of the devastated palace, which overlooks the Nile River, after days of heavy fighting with the Rapid Support Forces, or R.S.F., the powerful paramilitary group that the army has been battling.

“We’re inside!” shouted an unidentified officer as cheering soldiers swarmed around him in one video posted Friday morning. “We’re in the Republican Palace!”

Sudan’s information minister and its military spokesman confirmed that the palace, an emblem of power in Sudan for two centuries, was back in government control. “Today the flag is raised, the palace is back, and the journey continues until victory is complete,” the minister, Khalid Ali al-Aiser, wrote on social media.

Retaking the palace was a major symbolic victory for Sudan’s army, which lost most of Khartoum to the R.S.F. in the early days of the war in April 2023, leaving its forces confined to a handful of embattled bases scattered across the vast city.

It was also a significant boost to the military’s drive to expel the paramilitaries from Khartoum entirely, six months into a giant counteroffensive that has swung the balance of the war toward the military in the eastern half of Sudan.

Days earlier, the R.S.F. leader, Lt. Gen. Mohamed Hamdan, had vowed to stand his ground. “Do not think that we will retreat from the palace,” he said last week in a video address from an undisclosed location.

But the military and allied militias, which have gradually seized most of the northern and eastern parts of the city, pressed hard on their target. Early Thursday, the military launched a blistering ambush on an R.S.F. convoy south of the palace, apparently as R.S.F. troops attempted to flee, video footage showed.

Gunfire and explosions could be heard across the capital for much of Thursday.

On Friday, the victory celebrations were shared by the diverse Sudanese militias that fought alongside the army. They included hard-line Islamists; battle-tested fighters from the western region of Darfur; and some of the civilian revolutionaries who in 2019 helped oust Sudan’s authoritarian leader, President Omar Hassan al-Bashir, who had ruled for three decades.

“God is the greatest. We captured the Republican Palace,” wrote Misbah Abu Zeid, leader of the Bara Ibn Malik Battalion, an Islamist militia that played a frontline role as the battle moved into downtown Khartoum, on social media.

But the takeover came at a cost. A missile thought to be fired by the R.S.F. struck a crew from Sudan’s state television station as they were working outside the palace on Friday morning, killing two journalists and a driver. Two officers from the military’s media wing, including its top official, were also killed in the attack.

Sudan’s war erupted in April 2023 after months of tension between the military chief, Gen. Abdul Fattah al-Burhan, and General Hamdan of the R.S.F. The two men had seized power together in a military coup in 2021, but they could not agree on how to integrate their forces.

The R.S.F. had the upper hand for the first 18 months of the war, backed by external support from foreign sponsors including the United Arab Emirates and Wagner mercenaries from Russia.

But since the military launched a major counteroffensive in September, its forces have recaptured states in southeastern Sudan and gradually pushed the R.S.F. out of Khartoum.

After taking several strategic bridges on the Nile, the military seized the north and east of the city in recent months, before turning its sights on the presidential palace.

That sprawling compound, on the southern bank of the Blue Nile, has long occupied a central place in Sudan’s history. Established in the early 19th century under Ottoman-Egyptian colonization, the palace has been destroyed and rebuilt several times.

It was the scene of a famous colonial-era episode in 1885, when followers of a revolutionary cleric, Muhammad Ahmad, who was known as the Mahdi,, killed the British ruler of Sudan, Gov. Charles Gordon, on the steps of the palace.

In 2015, Mr. al-Bashir opened a new palace, funded and built by China, next to the colonial-era one. The new palace was also a focus of the tumult that followed the ouster of Mr. al-Bashir in 2019, when jockeying between civilian and military leaders led to the 2021 military coup.

Protected by the Republican Guard, the new palace was reported to have secret tunnels and rooms, and was the focus of most of the raucous celebrations on Friday.

As the R.S.F. fighters have withdrawn from eastern and northern Khartoum since January, the war’s grim toll has become starkly apparent.

Entire districts have become a charred wasteland, as New York Times reporters saw during the past week in the city.

Bullet-pocked vehicles lay scattered across deserted streets. Apartment blocks stood torched or looted, and banks were blown open. White smoke billowed from a giant wheat silo.

In the city center, army snipers trained their rifles through the windows of a deserted luxury apartment block overlooking the Nile. On the far bank, a riverboat slumped on its side. A surveillance drone buzzed overhead.

A lace curtain billowed around Sgt. Maj. Ismail Hassan as he peered through his binoculars at the bombed-out presidential palace, which sat amid a cluster of hollowed-out office blocks.

“They have many snipers deployed in the tall buildings,” Sergeant Major Hassan said. “That’s what makes it so hard.”

The R.S.F.’s best snipers came from Ethiopia, he added, citing military intelligence reports. A document found by The Times at a deserted R.S.F. base in the city, listing recent Ethiopian recruits, supported that idea.

By some estimates, the capital’s prewar population of about eight million has been reduced to two million. In recently recaptured areas, the army has moved residents to temporary camps on the edge of the city, where the army is screening for R.S.F. sympathizers, several residents said.

For those still in the city, there was a palpable sense of relief that the R.S.F. fighters were gone.

“In the days before they left, they demanded money,” said Kamal Juma, 42, as he tapped water from a broken pipe in the street. “If you couldn’t pay, they shot you.”

Mr. Juma mopped the sweat from his brow.

“We can’t take any more of this war,” he said.

Even if the military manages to drive the R.S.F. from Khartoum, there is little prospect of the war ending soon, analysts say.

What started as a power feud between the two generals has exploded into a much wider conflict fueled by a bewildering array of foreign powers.

In parts of the city, wild bushes sprouted in empty streets, adding to the apocalyptic air. Faded billboards, erected before the war, advertised goods at one-tenth of their current prices — a reflection of war’s crushing economic cost.

But the picture was markedly different in Omdurman, west of the Nile and controlled by the army. There, markets and restaurants were bustling, and even jewelry stores had reopened as residents streamed back.

Even in Omdurman, though, death is never far.

On Monday night, a volley of R.S.F. rockets landed in a quiet street where six neighbors had gathered under a palm tree to drink coffee after fasting for Ramadan.

After an explosion rocked his house, Moamer Atiyatallah stumbled through the cloud of dust, calling out to his friends under the palm tree, “What happened, guys?”

Nobody answered. All six men — a carpenter, an auto trader and a rickshaw driver, among others — had been killed, as well as two other men who were passing in the streets.

An hour after the strike, wailing women had spilled into the dark street, where stony-faced men picked up scraps of flesh from the ground and gathered them into plastic bags. A distraught young girl ran past.

“Father!” she screamed. “Father!”

Abdalrahman Altayeb contributed reporting.

The Israeli defense minister tried on Friday to turn up the pressure on Hamas to release more hostages, saying Israel was preparing to seize more territory in Gaza and intensify attacks by air, sea and land if the armed Palestinian group does not cooperate.

The remarks by the defense minister, Israel Katz, came days after a cease-fire that had been in place for more than two months was shattered with a renewed Israeli bombardment and more limited ground operations inside Gaza. More than 500 Palestinians have been killed since Israel restarted attacks on Tuesday, according to the Gaza Health Ministry, which does not distinguish between civilians and combatants.

“The more Hamas persists in its refusal, the more territory it will lose,” Mr. Katz said in demanding the release of more hostages.

He said the Israeli military could expand a security zone inside Gaza where its forces were already stationed and order more Palestinians to evacuate their homes. The captured territory would be held indefinitely by Israel, he added.

There were no immediate reports of new Israeli attacks with heavy casualties in Gaza on Friday. And mediators were still trying to prevent the new escalation of violence from snowballing back into a full-scale war.

Hamas said Friday that negotiations to return to the truce — which began in mid-January — were still ongoing. But it reiterated that any agreement to free more hostages would have to lead to a permanent end to the war, which Israel has been loath to commit to while the Palestinian militant group still is in charge of Gaza.

In Israel, domestic political turmoil over the war in Gaza intensified this week over a decision by Benjamin Netanyahu, the prime minister, to fire Ronen Bar, the head of the Shin Bet intelligence service. Protesters have criticized Mr. Netanyahu for what they call an attempt to purge the security establishment of those he perceives as disloyal.

On Friday, Israel’s Supreme Court issued an injunction freezing Mr. Bar’s dismissal until the justices could hear petitions that had been filed against it. The court ruled that the hearing would take place no later than April 8 — two days before the deadline for Mr. Bar’s exit.

Mr. Netanyahu’s allies quickly denounced the court for intervening as judicial overreach. If the court does strike down the government’s decision to dismiss the Shin Bet chief, the prime minister has yet to say whether he would uphold its ruling.

Over the past three days, Israeli forces have bombarded targets across Gaza, saying they were attacking Hamas sites and operatives. Israeli ground troops have seized a major corridor in central Gaza from which it withdrew during the cease-fire with Hamas, and they have expanded ground raids in northern and southern Gaza.

Hamas’s military response so far has been limited. Its military capabilities were significantly degraded by the war, although the group is still believed to command tens of thousands of armed fighters. Israeli officials say Hamas has been using the cease-fire to regroup, plan for future fighting and to plant explosive devices.

Hamas fired three rockets at Israel for the first time in months, but all were either intercepted or fell without causing casualties, a far cry from the barrages it could muster in the early months of the war.

Israel hopes to compel Hamas to free more of the remaining hostages seized in the Oct. 7, 2023, attack that ignited the war in Gaza. As many as 24 living captives — and the remains of more than 30 others — are still in Gaza, according to the Israeli government.

Even before the cease-fire collapsed this week, Israel had blocked humanitarian aid to Gaza, preventing shipments of food and medicine from reaching Palestinians still recovering from more than a year of hunger and wartime deprivation.

In the latest attacks, Israeli troops have not swept through Palestinian cities in Gaza, divided the enclave in two or forcibly evacuated northern Gaza en masse, as they did during the 15-month campaign against Hamas.

Israel has vowed not to end the war in Gaza without Hamas’s destruction. Hamas has said it is willing to hand over civilian responsibilities in the enclave, but it has refused to disband its battalions of armed fighters or send its leaders there into exile.

Diplomats, including from the United States, are hoping to broker at least a partial deal to bring both sides back to the cease-fire, free more hostages and allow humanitarian aid to begin flowing into Gaza again.

Before the Israeli offensive, Steve Witkoff, the Trump administration’s Mideast envoy, had proposed an extension of the initial cease-fire, which elapsed in early March, in exchange for the release of hostages.

In the meantime, the United States and other mediators would work to find a “durable solution to this intractable conflict,” Mr. Witkoff’s office said in a statement last week.

Israel said it had accepted Mr. Witkoff’s plan, which accorded with Israeli demands for the release of more hostages without an immediate commitment to ending the war in Gaza permanently. Hamas did not immediately agree to the deal, but said earlier this week that it had been considering the proposal.

In an interview on Thursday in Doha, Qatar, Husam Badran, a senior Hamas official, suggested the group was willing to show some flexibility over such an agreement — including by potentially releasing more hostages — to jump-start talks aimed at ending the war.

“The problem isn’t the numbers,” Mr. Badran told The New York Times. “We’re acting positively with any proposal that leads to the start of negotiations” over a permanent truce, he added.

Adam Rasgon and Patrick Kingsley contributed reporting.

When Dr. Shoo Lee, one of Canada’s most renowned neonatologists, wrote an academic paper in 1989, he never imagined it would one day help convict a British nurse of murder.

But more than three decades after his paper was published, that is what happened.

Lucy Letby, a former nurse in a neonatal unit in northern England, was found guilty in two trials in 2023 and 2024 of the murder or attempted murder of 14 babies in her care, and sentenced to life in prison, where she remains today.

The case rocked Britain, seeming to expose a remorseless serial killer who, prosecutors said, used a bizarre range of techniques to kill her tiny, often very premature, victims: Injecting them with air, overfeeding them with milk or contaminating their feeds with insulin.

For seven of the murder or attempted murder charges, the prosecution’s lead expert witness relied on Dr. Lee’s 1989 paper on a rare complication in newborns — pulmonary vascular air embolism — to argue that Ms. Letby had intentionally injected air into their veins.

The only problem? The expert witness had misinterpreted his work, Dr. Lee says.

“What they were claiming was that this baby collapsed and had skin discoloration, therefore that equals air embolism,” said Dr. Lee, 68, in an interview in London last month. But, he said, “That is not what the research shows.”

That realization set Dr. Lee on a moral mission to review Ms. Letby’s case. Working pro bono, he gathered 14 specialists from around the world to assess the clinical evidence. Last month, he revealed their explosive findings — that “there was no medical evidence to support malfeasance causing death or injury” in any of the babies that Ms. Letby was charged with harming.

“If there’s no malfeasance, there’s no murder. If there’s no murder, there’s no murderer,” Dr. Lee said, adding, “And if there’s no murderer, what is she doing in prison?”

Ms. Letby has exhausted her avenues to appeal in the courts. Her only hope now lies with a small, independent body, the Criminal Cases Review Commission, which is responsible for investigating possible miscarriages of justice.

‘I didn’t know whether she was innocent or guilty’

Dr. Lee, who retired in 2021 to a farm in rural Alberta, knew almost nothing about Ms. Letby’s case until an email landed in his inbox in October 2023.

Ms. Letby had always maintained her innocence, and her lawyer wanted Dr. Lee to review the medical evidence. “I thought it was spam at first, because how often do you get an email like that?” Dr. Lee said. After a second email, he realized the request was real.

Dr. Lee had spent his entire career focused on the youngest patients. After completing medical school in his native Singapore, he moved to Canada and trained in pediatrics before undertaking a neonatal fellowship at Boston Children’s Hospital and later a Ph.D. in health policy at Harvard.

In 1995, he created the Canadian Neonatal Network, connecting specialists from across the country to improve outcomes for newborns. He became pediatrician-in-chief at Mount Sinai Hospital, Toronto, and in 2019, he received the Order of Canada for introducing best practices that reduced infant mortality.

As he studied Lucy Letby’s trial transcripts, Dr. Lee immediately knew his research had been misinterpreted. “I didn’t know whether she was innocent or guilty,” he recalls. “But regardless of whether you’re innocent or guilty, you cannot be convicted on wrong evidence. That’s just wrong.”

He agreed to help with Ms. Letby’s request for an appeal, writing to England’s Court of Appeal and later providing live video testimony. But the court ultimately denied her request, saying Dr. Lee’s testimony should have been introduced at trial.

It was then that Dr. Lee decided to assemble a team of neonatal specialists to look into the case.

“This panel, you’re not going to find a better group of people,” he said, rattling off a list that included the head of neonatology at Children’s Hospital of Philadelphia, a former president of Britain’s Royal College of Pediatrics and the former director of the neonatal intensive care unit of Boston Children’s Hospital.

The key caveat Dr. Lee insisted on was that the panel’s review would be released no matter their findings — even if they strengthened the case that Ms. Letby was guilty.

‘You’re going to get disasters’

The experts, who all worked on a voluntary basis, forensically assessed the cause of death or deterioration for each of the 17 babies whom Ms. Letby was initially charged with murdering or attempting to murder.

Two experts separately examined the medical notes of each baby. If their assessments differed, a third expert was brought in. The process was painstaking and took four months. But the final results were clear, Dr. Lee said. “In all cases, death or injury were due to natural causes or just bad medical care,” he told the news conference last month.

In the case of one baby, for instance, the prosecution argued at trial that she had been stable and had died from an injection of air into her IV line, causing an embolism. But the independent review found, based on her medical records, that she had died of sepsis and pneumonia, and that the mother, who went into labor prematurely, had not been given antibiotics to prevent infection.

In another case, a baby born at 25 weeks was intubated using the wrong size of endotracheal tube. While the prosecution alleged that Ms. Letby attempted to murder the infant by dislodging the tube, the experts found the baby’s condition deteriorated because of injury caused by intubation with a tube that was too large, and because a doctor did not understand “the basics of resuscitation, air leak, mechanical ventilation, and how equipment that were commonly used in the unit work.”

Some of the hospital staff, the panel concluded, were caring for the most critically ill or premature babies in a unit that was only meant to treat babies with lesser needs.

“You’re asking doctors in places without the expertise, without the infrastructure, to look after babies that they they’re not prepared to do,” Dr. Lee said. “And if you do that, then you’re going to get disasters.”

Nobody ever saw Ms. Letby harming a baby, and major questions were first raised about her guilt in a New Yorker article in May 2024. In the months since, dozens of experts in medicine and statistics have voiced concerns about the evidence.

Dr. Dewi Evans, the prosecution’s lead expert witness, did not respond to requests for comment, but he has publicly criticized the panel’s work and said he stands by his testimony.

The Countess of Chester Hospital, where the deaths took place, said it was focused on an ongoing police investigation and on a public inquiry that was set up by the government last year to investigate how a serial killer could get away with such crimes for so long. Earlier this week, the hospital’s former managers requested a halt to that inquiry, in the wake of Dr. Lee’s review, but the judge refused, saying that the inquiry was never focused on examining Ms. Letby’s guilt.

Mark McDonald, Ms. Letby’s current lawyer, plans to include Dr. Lee’s full expert report in his application to the Criminal Cases Review Commission, which can refer cases back to the Court of Appeal. The commission said in a statement last month that it had “received a preliminary application in relation to Ms. Letby’s case, and work has begun to assess the application.”

The mother of a child whom Ms. Letby was convicted of attempting to murder denounced the expert panel’s assessment, and a spokesman for the C.C.R.C. asked “that everyone remembers the families affected.”

Dr. Lee insisted that those families were one of his central concerns as he analyzed the cases, after spending four decades caring for babies.

“I can tell you one thing: Families want to know the truth,” he said. “They want to know the truth, regardless of whether it is painful or not painful. They want to know what really happened.”