At least 50 people were killed in clashes between security forces and protesters on Sunday in Bangladesh, as the country’s leaders imposed a new curfew and internet restrictions to try to quell a growing antigovernment movement.

The revival of student protests after a deadly government crackdown late last month, as well as a call by the governing party for its own supporters to take to the streets, has plunged the country of over 170 million into a particularly dangerous phase.

The exact number of deaths in the violence on Sunday was unclear. A diplomatic official in Dhaka said the toll across Bangladesh was in the 60s, while tallies by local news media and a statement from the protest coordinators put the count at anywhere from 50 to 74. At least 13 of the dead were police officers, the country’s Police Headquarters said in a statement.

Sunday’s toll added to the more than 200 people killed in the crackdown on protesters last month by security forces under Bangladesh’s increasingly authoritarian leader, Sheikh Hasina. In a sign of the risk of further violence, the protest coordinators said they would march toward Ms. Hasina’s official residence on Monday.

Over the weekend, the tensions flared into the kind of localized clashes across the country that appeared difficult to contain. With the public already angry at the police forces, seeing them as an overzealous extension of Ms. Hasina’s entrenched authority, attention focused on Bangladesh’s powerful military.

Ms. Hasina has worked to bring the military to heel. But it has a history of staging coups and was being watched for how it positions itself in the escalating crisis.

What began as a peaceful student protest last month over a preferential quota system for public-sector jobs has morphed into unprecedented anger at Ms. Hasina’s growing autocracy and her management of the economy.

While the crackdown, which included the arrests of more than 10,000 people and the lodging of police cases against tens of thousands more, temporarily dispersed the protesters, the demonstrations have been back in full force since Friday.

The protesters’ anger over the large numbers of deaths has solidified their demands to a single point: On Saturday, at a rally of tens of thousands, they demanded the resignation of Ms. Hasina, who has been in power for the past 15 years.

In response to the resignation call, her Awami League party called on its supporters to join counterprotests — setting up the tense situation that unfolded on Sunday.

In a statement sent to the news media on Sunday, as internet restrictions went into effect, leaders of the student movement called for the protests to continue uninterrupted.

“If there is an internet crackdown, if we are disappeared, arrested, or killed, and if there is no one left to make announcements, everyone should continue to occupy the streets and maintain peaceful noncooperation until the government falls in response to our one demand,” Nahid Islam, one of the movement’s leaders, said in the statement.

As the chaos escalates, with both the protesters and Ms. Hasina’s governing party digging in their heels, and as opposition parties take the opportunity to pile on, the country’s military may help determine what happens next.

The army and other security forces were deployed during the crackdown in July. On Sunday, however, the army’s chief, Gen. Waker-uz-Zaman, gathered senior officers for a meeting that was seen as an attempt to allay concerns over the army’s position in the crisis and reinforce its neutrality.

In a statement issued after the meeting, the army said its chief had reiterated that “the Bangladesh Army will always stand by the people in the interest of the public and in any need of the state.”

Reports from student protesters and diplomatic officials about the army’s conduct on Sunday were mixed. While in some parts of the country the army cracked down on the protesters, in other places, it was seen protecting the protesters against attacks by the governing party’s youth wing.

In announcing the reinstatement of the curfew, the army said it would “carry out its pledged duties in accordance with the Constitution and the country’s prevailing laws.”

While the army was long prone to staging coups, it has grown more disciplined in recent years, exercising its influence from behind the scenes.

Analysts attribute that to a combination of factors: Ms. Hasina’s stacking of the top ranks with loyalists, and the lucrative business of United Nations peacekeeping, to which Bangladesh’s army is a major contributor. Human rights abuses like those attributed to other forces under Ms. Hasina, or involvement in a coup, would have international ramifications.

In an indication of the growing pressure on the army to stick to a neutral position, dozens of former officers — including a former army chief — held a news conference on Sunday in Dhaka, calling on the military to withdraw its forces from the streets.

“We are deeply concerned, troubled and saddened by all the egregious killings, tortures, disappearances and mass arrests that have been tormenting Bangladesh over the past three weeks,” Iqbal Karim Bhuiyan, who served as army chief from 2012 to 2015, said in a statement on behalf of the former officers. “In no way our armed forces should come forward to rescue those who have created this current situation.”

Shayeza Walid contributed reporting from Dhaka.

Follow our latest updates on the Middle East crisis here.

First came the death of its top leader abroad, Ismail Haniyeh, by a bomb planted in Tehran. Then came Israel’s announcement that, only weeks earlier, it had killed Hamas’s most elusive and revered military leader. All of this as Israel continues to wage the deadliest war Palestinians in the Hamas-ruled Gaza Strip have ever faced.

At first tally, the latest score in the 30-year struggle between Israel and Hamas looks like a devastating one for the Islamist movement, one that throws its future into question. Yet the history of Hamas, the evolution of Palestinian militant groups over the decades and the logic of insurgencies more broadly suggest that not only will Hamas survive, it may even stand to emerge politically stronger.

Analysts and regional observers in contact with Hamas leaders see the latest blows it has suffered — including Mr. Haniyeh’s assassination, widely believed to be at Israel’s hand — as offering Israeli forces a short-term victory at the cost of long-term strategic success.

“Instead of creating the disconnect they’d hoped for, one that would make people fearful or completely defeated, this will have the opposite effect,” said Tahani Mustafa, a senior Palestine analyst at the International Crisis Group, which provides policy analysis on ending conflicts. “Israel just dealt them a winning hand.”

The military campaign Israel has waged in retaliation for Hamas’s Oct. 7 attacks has displaced some 90 percent of Gaza’s two million residents, razed swaths of the enclave’s cities and killed 39,000 people, according to Gaza’s health ministry, which does not distinguish between civilians and combatants.

Despite that, Hamas not only remains operational, but is recruiting new fighters both in Gaza and beyond, local residents and analysts say. Militants have also begun to re-emerge in areas that Israel had driven them out of months before.

For Hamas, the logic of insurgency means that simply surviving in the face of a far more powerful military provides a symbolic victory. With that comes a chance at staying power that outlasts any pain Israel has inflicted.

On Wednesday, Israel’s military said that a strike it conducted on July 13 had killed Muhammad Deif, the head of Hamas’s military wing, who is seen as an architect of the Oct. 7 attack on Israel. Hamas has yet to confirm the killing. Mr. Deif’s death, however, would represent the end of a yearslong Israeli effort to kill the man who is effectively the second-most senior leader after Israel’s most-wanted man, Yahya Sinwar, the head of Hamas in Gaza.

Israel’s announcement of Mr. Deif’s killing came on the day that mourners were gathering to bid farewell to Mr. Haniyeh, who was killed while on a visit to attend the inauguration of Iran’s new president. Both Iran and Hamas have accused Israel, with a long history of assassinating its foes, of being behind his death.

His loss, too, will be difficult for Hamas. Mr. Haniyeh was seen by regional analysts as a more moderate figure within the Islamist movement, acting as a bridge between its rival factions. He was also seen as a leader willing to push for mediation — including the continuing, if faltering, cease-fire talks with Israel.

“You take him out and the message is: Negotiations don’t matter,” said Khaled Elgindy, an expert on Palestinian affairs at the Middle East Institute in Washington.

“I don’t see a reason to conclude Hamas could become irrelevant,” he said. “The question is: How does Hamas change after this? And I think there is a very strong argument to be made that the leadership becomes more hard-line.”

Mr. Deif himself replaced Ahmed al-Jabari, the military leader Israel killed in 2012 with a targeted strike on his car. At the time, he was leading Hamas’s side in a mediation effort to reach a long-term cease-fire with Israel.

Israel’s decades-long targeted killing campaigns against its Palestinian and regional rivals have a contested record: Critics have long argued the tactic has simply created room for new parties or leaders to emerge as Israel’s main foes — often with ever more radical forces replacing them.

In the 1970s, Israel killed Wadi Haddad, the military leader of the communist Popular Front for the Liberation of Palestine, which led to that group’s collapse. A decade later, a new Palestinian foe had replaced it: Yasser Arafat’s nationalist force, Fatah. Israel killed its popular military leader, Khalil al-Wazir, but failed to cripple the group.

Hamas, founded in 1987, has intently studied the history of Palestinian militant groups in the hopes of avoiding their fates.

Since the early 2000s, Hamas has become the group seen by Palestinians as taking up the mantle of armed resistance to Israeli occupation while other groups’ military abilities have faded — or, in the case of Fatah, abandoned militancy as its primary strategy in favor of negotiations.

As peace talks broke down in the early 2000s, Hamas’s potency grew. Several Israeli assassinations of its leaders, including its co-founders, failed to derail the group.

Mr. Haniyeh’s life story provides a different lesson in the unintended consequences of some of Israel’s attempts to incapacitate Hamas. He was among 400 Palestinians expelled by Israel from Gaza to southern Lebanon, then under Israeli military occupation. Instead of being sidelined, figures like Mr. Haniyeh gained further popularity — and a broader regional reach.

Perhaps the most important principle for Hamas’s survival, Ms. Mustafa, the analyst, said, is not being overly reliant on material support from its foreign backers — a dependency that allowed Israel to deplete the Palestine Liberation Organization in the 1970s and 1980s, she said.

Hamas so far appears to have maintained that self-reliance even amid Israel’s tightened siege on Gaza. Iran is a major source of Hamas’s money and weapons — its attack drones were used by Hamas on Oct. 7. But now Iran is also struggling to keep itself from being dragged into a regional war.

Hamas militants have their own engineers who know how to make use of whatever they can find on the ground — from supplies looted from Israeli bases or ambushes on Israeli vehicles, or from extracting materials from unexploded ordnance and fallen drones.

“They got a lot of external support in terms of finance and training, but in terms of their logistics, a lot of that is homemade,” Ms. Mustafa said. “Which is why, even now, almost 10 months in, you haven’t seen the resistance wane.”

Not all Hamas observers believe that Hamas can survive the current pressures. Some analysts, like Michael Stephens at the London-based research group the Royal United Services Institute, believes the strikes will cause enough temporary damage to force Hamas into more concessions.

Akram Atallah, a Gazan political analyst at the Arabic newspaper Al-Ayyam, said Hamas would emerge from this war badly damaged — not only militarily, but in terms of support in Gaza, the region that “has always been its center of gravity.”

Much of the popularity Hamas is perceived to have gained, he said, has come from outside Gaza — such as from fellow Palestinians in the occupied West Bank.

“That is understandable for one obvious reason: It’s the residents of Gaza who are paying the price,” he said.

Hamas, he said, will never be able to lead the Gaza Strip after Israel’s offensive ends. Not only Israel and its main backers in Washington would reject this, he said, but Gazans themselves as well.

Yet even with that resolve, Hamas’s opponents have done little to ensure that anyone could replace Hamas, Mr. Stephens said.

“No one wants to go there, because no one wants to own that problem. Who is going to own the Palestinian question?” he said. “It looks bad for Hamas right now — but then, what exactly are the alternatives?”

Ms. Mustafa predicts an extended period in which Gaza is trapped in a power vacuum, with Israel entering and withdrawing from pockets where Hamas militants re-emerge and disappear.

Even if Israel were to ultimately deal a decisive blow against Hamas, Mr. Atallah said, the only question would be who emerged next.

“As long as there is an occupation, Palestinians will keep fighting,” he said, “whether there is still a Hamas, or there isn’t.”

President Volodymyr Zelensky of Ukraine said on Sunday that his army had received a first batch of F-16 fighter jets. The long-awaited arrival of the Western-supplied jets should bolster the country’s defenses, although Kyiv appears to have received too few of them so far to have an immediate impact on the battlefield.

“F-16s are in Ukraine. We did it,” Mr. Zelensky said in a video posted on social media networks showing him at an air base addressing and meeting Ukrainian pilots. He was standing in front of two F-16s, and two more flew overhead as he spoke.

At the very least, the arrival of the jets will boost Ukrainians’ morale, which has been dampened by months of slow but steady Russian advances on the battlefield and devastating attacks on the country’s power grid.

Mr. Zelensky said Ukrainian pilots “have already started using them for our country,” but he did not say whether they had already flown combat missions in Ukraine. Nor did he say how many jets had arrived in the country.

Ukraine hopes the F-16s, highly versatile aircraft equipped with advanced radar systems and a variety of weapons, will help turn the tide on the battlefield, where Russia has held the upper hand for much of the past year.

The presence of the jets will pose a new threat to Russian pilots and help deter them from entering Ukrainian airspace to attack troops on the front line and in cities. The F-16s are also expected to improve Ukraine’s ability to shoot down Russian missiles, easing the pressure on its weakened air defense systems.

The United States has agreed to arm the F-16s with missiles and other advanced weapons, which should help Ukraine conduct more long-range strikes behind Russian lines, said Nico Lange, a military expert and former German defense official.

Still, a shortage of trained pilots and the limited number of jets will constrain their immediate battlefield impact, experts say.

Western officials said earlier this year that as few as six jets might arrive in Ukraine by the summer. About 20 Ukrainian pilots are expected to be capable of flying the jets this year, according to U.S. officials. That would allow Ukraine to deploy only about 10 F-16s in combat, given that each aircraft requires at least two pilots.

John F. Kirby, the White House national security spokesman, told the Ukrainian edition of Voice of America last week that the planes would be “ready to fly by the end of the summer,” adding, “There’s no reason to doubt that.”

The deployment of the first F-16s caps more than two years of intense lobbying by Ukraine to acquire the American-made jets, which represent a significant upgrade over the Soviet-era aircraft that the Ukrainian Air Force has been using.

Initially, the Biden administration resisted the request for the F-16s over fears of escalating the conflict. But it reversed its stance about a year ago, allowing Western allies to transfer the jets to Ukraine. Since then, Western countries have pledged about 80 jets to Kyiv, though the vast majority of them will arrive over the coming years.

“We often heard the words that this is impossible,” Mr. Zelensky said on Sunday. “But we have made possible what was our ambition, our defense need.”

“Now it is a reality,” he said of the jets’ arrival. “Reality is in our skies.”

Ukrainian officials have warned that delays in deliveries of the F-16s could diminish the jets’ impact on the battlefield, giving Russia time to adapt its tactics. In recent weeks, Russia has targeted Ukrainian air bases in an apparent effort to limit the use of the F-16s ahead of their arrival.

At least four people were dead and 23 others were missing on Sunday, a day after a flash flood and landslide struck the city of Kangding in a mountainous part of Sichuan Province in southwestern China. It was the latest in a recent series of deadly events in China involving extreme weather.

State media reported early Sunday morning that at least 939 people had been relocated from the area because of the flooding. The majority of people in the region are Tibetans.

Among the missing were some people who had been on an expressway bridge near the city, between two mountain tunnels. The bridge collapsed amid heavy rain early Saturday, and three vehicles and five people were still unaccounted for as of Sunday.

A torrent of mud and water rushed into the area with force from a high elevation, according to state media. A photograph released by the official Xinhua news agency showed mud and broken pieces of roadway cascading down a steep slope where a vehicle lay on its side.

The Ministry of Emergency Management sent officials to the area to oversee a rescue effort that involved more than 1,400 people, 215 vehicles, search and rescue dogs and a helicopter.

Extreme weather has hit several parts of the country in recent weeks, taking a toll on lives and property.

At least 30 people were killed late last month when heavy rain from Typhoon Gaemi lashed Hunan Province in southern China, causing widespread flooding. According to state media, 35 people remained missing as of Thursday. Close to 100,000 people had to evacuate. By the weekend, power, transportation and communication had largely been restored to eight villages that had been cut off by flash floods and landslides.

About two weeks ago, 38 people died when part of a highway bridge collapsed during a period of heavy rain in western China. As of Friday, 24 people remained missing, according to the official Xinhua news agency.

In June, at least 47 people died as a result of flooding and landslides in southern China’s Guangdong Province. More than 100,000 people were evacuated after the city of Meizhou experienced “once-in-a-century” rainfall, according to state media.

Adding to the suffering, July was the hottest month recorded in China since the country began collecting data in 1961. Higher than average temperatures were reported in every province in China.

The Chinese government has allocated more than $1.6 billion in disaster relief funds to local governments so far this year.

The landslide on Saturday severed two of the area’s main transportation routes during the summer tourist season. Feng Fagui, a local official, said that a working group had been set up to serve tourists and truck drivers in the area who were stranded by the road closings.

After they spread pink petals on golden statues of Ganesh and Shiva, and recited prayers to blue-skinned and eight-armed gods, the Hindu faithful left their temple and headed to a party for another one of their divinities — the Catholic St. Rosalia.

“To the other goddess!” said Swasthika Sasiyendran, 23, after she changed from her gold-and-white sari into a T-shirt bearing Rosalia’s face.

Every year, in the height of Sicily’s summer heat, Palermo fills with festival lights and honking scooters as people gather to celebrate Rosalia, the city’s patron saint. Among the hundreds of thousands who join the procession, which culminates with a towering statue of the saint being carried through the streets, are members of the city’s Sri Lankan Tamil community, some of Rosalia’s most ardent worshipers.

Palermo is prone to this kind of medley. It is a city that sits between continents, shaped by the overlapping of Greek, Byzantine, Arab, Norman and Spanish civilizations, which hundreds of years ago made it a cosmopolitan, open and refined metropolis.

The blurring of lines between faiths, origins and traditions stands in stark contrast to a growing political discourse in Italy and Europe that insists on firm borders between nations and religions, and immutable identities.

In recent decades, Palermo has welcomed a new generation of immigrants, including thousands of Tamils, both Catholic and Hindu, who fled civil war and came to look for work, forming one of the biggest communities in Italy.

While segregation and discrimination remain in many quarters of the city, locals say Palermo has kept some of its tolerance and openness. The shabby and affordable city center has allowed foreigners to settle in, rather than being segregated in only the suburbs. The downtown Ballarò market has quickly absorbed stands selling plantains and cassava alongside those offering traditional fried chickpea patties and boiled octopus. Many groups promoting dialogue between cultures have sprung up.

While some praise Leoluca Orlando, who was the city’s progressive mayor for more than 20 years, for sending out a message of inclusion, many Tamils credit someone else.

“Santa Rosalia,” Ms. Sasiyendran said. “She welcomes everybody.”

Palermo’s Hindu Tamils, most of whom are originally from Sri Lanka, have added the Catholic saint to their colorful pantheon of gods. Many are attracted to her reputation for miracles, especially for saving the city from a plague in the 17th century. They are also drawn to her mystical sanctuary, a cave on a mount north of the city where she is said to have died after escaping an arranged marriage.

Most of the pilgrims who visited the cave on a recent Sunday were Tamils. In the shrines that many Tamils have in their homes, the image of Rosalia in a monk’s habit features alongside images of Hindu gods like Lakshmi, wrapped in golden necklaces, her legs crossed on top of a lotus flower.

“Santa Rosalia is like our mother,” said Tharsan Mahadevar, the secretary of the Hindu temple, as he sat eating lentils and a spicy vegetable curry while wearing a shiny sarong, the image of Ganesha tattooed on his arms and chest.

Like many other Tamils, Ms. Sasiyendran’s father, Sasi, came to Palermo in the 1990s from Sri Lanka, which was then ravaged by civil war. He did not have a Hindu temple in Palermo, or a place of worship to attend, except for the peaceful Santa Rosalia sanctuary atop Mount Pellegrino. Surrounded by umbrella pines, the site reminded him of the temples back home, hidden in the green mountains of northern Sri Lanka.

He and other lonely, scared men, including many Catholic Tamils, began calling Rosalia “Madonna,” a mother who welcomed them to Palermo. Three days after Ms. Sasiyendran’s mother traveled from South Asia to Palermo to marry her father, he took her to the sanctuary, which he had begun calling Mazhai Kovil Madha, or “Mountain Church Mary.”

Over the years, their Hindu temple was built, wedged between short buildings and bleached awnings near Palermo’s shipyards, but Mr. Sasiyendran continued turning to Rosalia for help and comfort.

When he died of a lung disease in 2022, he was holding a statue of the Madonna, his daughter said.

“I think he is with her now,” said his wife, Eswari Sasiyendran, as she stood in their apartment in Palermo, where a key holder decorated with Rosalia hung alongside a shrine with golden statues of Ganesh. Ms. Sasiyendran said she had resisted pleas from her family to leave Palermo and return home since she had been widowed.

“I have got someone here to pamper me,” she said, referring to the saint.

She added: “Mother doesn’t see fair son or Black daughter. For her, everyone is equal.”

The Sasiyendran family credits the saint with an array of favors, including catching flights, finding forgotten bags and protecting their father when he was still sleeping on benches in Palermo’s parks. Many of the Tamils who climbed up the mountain on a recent morning — who were afforded a stunning view of Palermo in the rosy dawn light — also came with gratitude.

Kuganathan Kanagasingam, 54, said that when his wife had depression in 2022, he began walking up the mountain every Sunday at 5 a.m. — even in the pouring rain or scorching heat.

“Now she is well,” he said. “The medicines do a part, God does the other,” he said, before kissing the steps leading to Rosalia’s cave.

Alongside the cave hung baby shoes, ultrasound photographs and silver figurines of organs the saint had healed, among other votive paraphernalia.

Kiru Ponnampalam, 48, a Tamil cleaner, lit a red candle and placed it in front of Rosalia’s statue. He said he had been married for 10 years with no children until he began going to the sanctuary, when he finally managed to have a child, Abi, who is now 6.

“It was a miracle by Santa Rosalia,” he said.

Academics who have studied the community say that the Tamils’ devotion to Rosalia has provided a way to legitimize themselves and to be accepted by Sicilians.

“It was a way for them to become visible,” said Eugenio Giorgianni, an anthropologist at the University of Messina. “To enter the public space.”

Agostino Palazzotto, 62, an Italian volunteer at the sanctuary, watched on as a long line of Tamils climbed up the church’s stairs.

“I believe in the Santuzza,” he said, using a local nickname for the saint. “They believe in her A LOT.”

Polytheistic religions like Hinduism have the benefit of allowing for the continual incorporation of new gods. Pagan Romans venerated a mix of Greek, Egyptian and Persian gods, in addition to their own emperors.

“Santa Rosalia was a person,” said Mohan Thampiaijah, 56, another Tamil pilgrim. “Vishnu is blue and Ganesh is an elephant.” He paused. “I haven’t heard of any other differences.”

A family of Tamil pilgrims, after wetting their hands with holy water from a spring in the sanctuary, went to change from their cotton dresses into elaborate red-and-gold saris before heading to the Hindu temple. Others soon joined them, some still wearing plastic Christian crosses.

That evening, they headed to Rosalia’s annual party, where they mixed with Sicilians, tourists, street vendors and loudspeakers blasting Italian summer hits. They watched the fireworks and admired Rosalia’s statue: Like the Hindu goddess Lakhsmi, she was wrapped in flower petals, a lily this time.

“I really don’t see that big of a difference,” said Dhanja Kirupakaran, 20 — who, according to her mother, was born because of a miracle by the saint.

The private jet that took off from southwest Germany on Thursday afternoon was carrying a group that may have never expected to be confined together: police officers, doctors, intelligence agents, a senior aide to Germany’s chancellor — and a convicted Russian assassin.

In the back of the plane, the assassin, Vadim Krasikov, sat with his hands and feet bound and wearing protective headgear; he was not heard uttering a word on the entire flight.

At the same time, a Russian government jet was also headed for Ankara, Turkey’s capital, carrying officers from the F.S.B. intelligence agency and 16 prisoners being released by Russia and Belarus. At one point, one of the F.S.B. escorts made what seemed like a bad joke to the two best-known Russian dissidents on board: “Don’t have too much fun out there, because Krasikov could come back for you.”

This account of the tense hours surrounding the exchange — the biggest between Moscow and the West since the Cold War — is based on new details revealed by Western government officials involved in the process, and on early testimony from the Russian political prisoners released as part of the deal.

The swap freed Mr. Krasikov, the American journalist Evan Gershkovich and 22 others in a complex seven-country deal that required intricate planning and timing. The successful transfer highlighted the ability of some of the world’s most powerful intelligence agencies to cooperate on a distinct operation of shared interest, even as Russia and the West engage in a tense standoff over the war in Ukraine.

Last month, C.I.A. officers met with F.S.B. counterparts in Turkey to agree on the final terms of the swap, and also to plan the dizzying logistics for how it could actually be carried out on the tarmac in Ankara.

But even in the final hours, the Western officials said, the Americans and Germans worried that something could go wrong — for example, that Russia might not deliver the agreed-upon roster of prisoners or swap in look-alikes.

Near the front of the jet carrying Mr. Krasikov from Germany’s Karlsruhe airport, the foreign policy adviser to Chancellor Olaf Scholz, Jens Plötner, was going over contingencies with the German team. Forensics experts would visually identify the 13 Russian and German prisoners to be handed over to Germany, some of whom hadn’t been seen in public for years.

In coordination, the American plane bound for Turkey took off from Dulles Airport outside Washington, D.C., carrying American officials, medical staff and a psychologist trained to treat the effects of long term captivity. Three Russian prisoners being released by the U.S. were guarded by officers of the Marshals Service.

For those being freed by Russia, the day began at Moscow’s Lefortovo jail, where they had been gathered from prisons as far away as Siberia. Aleksandra Y. Skochilenko, imprisoned for opposing the war in Ukraine, had been driven there from St. Petersburg along with Andrei Pivovarov, another political prisoner; when Mr. Pivovarov saw her, she recalled in an interview on Saturday, he deduced that they would probably be exchanged and told her, “All will be well.”

“Gather your things,” a prison guard told Ms. Skochilenko on Thursday morning.

She said she was taken downstairs to a waiting group of F.S.B. agents with their faces covered, who led her onto a bus. Despite the officers insisting they be quiet, the prisoners talked among themselves about who else was with them and who was not.

Even after an official announced, “This is a political exchange,” Ms. Skochilenko wasn’t ready to believe it. She had been lied to so many times in prison, she said, that the thought crossed her mind: “They’re going to drive us to a forest now and shoot us.”

At Moscow’s Vnukovo airport, some prisoners boarded the plane wearing only their prison robes. One of them, the opposition politician Ilya Yashin, said all he could bring were a toothbrush, toothpaste and his robe. Another, Vladimir Kara-Murza, appearing at a news conference on Friday with Mr. Yashin, said he traveled in long johns, an undershirt and rubber shower slippers.

On the plane, there was no food served, even as the accompanying F.S.B. agents in plainclothes snacked on lunches they appeared to have packed at home, Ms. Skochilenko said. The American and German prisoners all appeared to be seated in the business class section of the plane, she said; she and the other Russian political prisoners flew economy.

At one point, one of the F.S.B. agents made the crack to Mr. Yashin and Mr. Kara-Murza about Mr. Krasikov coming back to kill them, Mr. Yashin recalled.

“It was a joke, of course, an unpleasant kind of joke that does make your skin crawl a little bit,” Mr. Yashin said.

The plane landed in Ankara in coordination with multiple private jets: the one from Germany, the one from Dulles airport, and one each from Poland, Slovenia and Norway, which were also releasing prisoners to Russia.

A complex choreography ensued, the Western officials and Ms. Skochilenko said. Overseeing the operation was Turkey’s MIT spy agency, whose chief, Ibrahim Kalin, was monitoring it remotely. On the ground were Turkish agents in dark suits and sunglasses.

The American delegation on the tarmac comprised officials from the White House, F.B.I., C.I.A. and the State Department. Among the group was David Cotter, an F.B.I. agent who until recently was the National Security Council’s director for hostage and detainee affairs.

The American team stayed in touch with National Security Adviser Jake Sullivan by secure, encrypted telephones.

Footage released by Russia showed German officers walking Mr. Krasikov — still wearing a helmet, in accordance with typical German practice in the transport of dangerous prisoners — to a white bus on the tarmac. The other seven prisoners being released by the West, as well as the two children of the Russian spies freed by Slovenia, were taken to the same bus.

The three released Americans — Mr. Gershkovich, the security contractor Paul Whelan and the journalist Alsu Kurmasheva — were taken onto a second bus. The other 13 prisoners being released by Russia, including Ms. Skochilenko, Mr. Kara-Murza, Mr. Yashin and several German nationals, were brought onto a third.

German forensic experts then boarded the bus carrying those being freed by Russia to verify their identities. Ms. Skochilenko said one of them asked her name and date of birth and examined her face from different angles, checking it against photographs of her that appeared to have been printed out from the internet.

Once the Americans were certain the Russians had delivered on their end of the deal, they gave signed clemency papers to the three Russian prisoners in their custody. The Germans also gave the Turks the green light. Ms. Skochilenko said she watched through the bus window as the Russians being released by the West boarded their plane to Moscow.

The Russian jet took off quickly, headed back to Vnukovo airport, where a red-carpet welcome by Mr. Putin and an honor guard awaited them.

Those released by Russia were whisked to a secure airport building, where they could finally eat and make brief calls. The swap had been so secret that some relatives of the Russian political prisoners were in the dark about whether their loved ones would be freed.

“Do you realize what’s happening?” Oleg Orlov, the co-chairman of the human rights group Memorial, asked his wife Tatyana Kasatkina when he called her, she said.

The three freed American prisoners then boarded the plane, which made its way back to Joint Base Andrews in Maryland. From there, they would fly to San Antonio, Texas, to a facility run by the military that specializes in PISA — post isolation support activities. There, they are expected to spend days under supervision as they try to readjust to normal life.

Mr. Plötner, the German chancellor’s aide, told the 13 German and Russian released prisoners that they would be flying to Cologne. They would be greeted at the airport by Mr. Scholz, provided with German travel documents if necessary, and taken to a military hospital in the nearby city of Koblenz.

In one last precaution, their bags — to the extent they had any — were X-rayed before being loaded onto two planes.

“I wanted to cry,” Ms. Skochilenko said. “But I couldn’t.”

Reporting was contributed by Philip Kaleta from Washington, Ben Hubbard from Istanbul, Valerie Hopkins from Cologne, Germany, Ekaterina Bodyagina and Christopher F. Schuetze from Berlin, and Lauren Leatherby from London.