Ukrainian President Volodymyr Zelenskyy planned to speak Tuesday to U.N. Security Council diplomats outraged by growing evidence that Russian forces have deliberated killed civilians, many of them shot in yards, streets and homes, and their bodies left in the open.

The withdrawal of Russian troops from towns around Ukraine’s capital revealed the corpses, which led to calls for tougher sanctions against the Kremlin, especially a cutoff of fuel imports from Russia. Germany and France reacted by expelling dozens of Russian diplomats, suggesting they were spies. U.S. President Joe Biden said Russian leader Vladimir Putin should be tried for war crimes.

“This guy is brutal, and what’s happening in Bucha is outrageous,” Biden said, referring to the town northwest of the capital that was the scene of some of the horrors.

The discovery of bodies in Bucha was expected to be “front and center” at the Security Council session, said Barbara Woodward, the U.N. ambassador for the United Kingdom, which currently holds the council presidency.

Associated Press journalists in Bucha counted dozens of corpses in civilian clothes and apparently without weapons, many shot at close range, and some with their hands bound or their flesh burned.

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After touring neighborhoods of Bucha and speaking to hungry survivors lining up for bread, Zelenskyy pledged in a video address that Ukraine would work with the European Union and the International Criminal Court to identify Russian fighters involved in any atrocities.

“The time will come when every Russian will learn the whole truth about who among their fellow citizens killed, who gave orders, who turned a blind eye to the murders,” he said.

Russian Foreign Minister Sergey Lavrov dismissed the scenes outside Kyiv as a “stage-managed anti-Russian provocation.” Kremlin spokesperson Dmitry Peskov said the images contained “signs of video forgery and various fakes.”

Russia has similarly rejected previous allegations of atrocities as fabrications on Ukraine’s part.

Ukrainian officials said the bodies of at least 410 civilians have been found in towns around Kyiv that were recaptured from Russian forces in recent days.

The Ukrainian prosecutor-general’s office described one room discovered in Bucha as a “torture chamber.” In a statement, it said the bodies of five men with their hands bound were found in the basement of a children’s sanatorium where civilians were tortured and killed.

The bodies seen by AP journalists in Bucha included at least 13 in and around a building that local people said Russian troops used as a base. Three other bodies were found in a stairwell, and a group of six were burned together.

The dead witnessed by the news agency’s journalists also included bodies wrapped in black plastic, piled on one end of a mass grave in a Bucha churchyard. Many of those victims had been shot in cars or killed in explosions trying to flee the city. With the morgue full and the cemetery impossible to reach, the churchyard was the only place to keep the dead, Father Andrii Galavin said.

Tanya Nedashkivs’ka said she buried her husband in a garden outside their apartment building after he was detained by Russian troops. His body was one of those left heaped in a stairwell.

“Please, I am begging you, do something!” she said. “It’s me talking, a Ukrainian woman, a Ukrainian woman, a mother of two kids and one grandchild. For all the wives and mothers, make peace on Earth so no one ever grieves again.”

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Another Bucha resident, Volodymyr Pilhutskyi, said his neighbor Pavlo Vlasenko was taken away by Russian soldiers because the military-style pants he was wearing and the uniforms that Vlasenko said belonged to his security guard son appeared suspicious. When Vlasenko’s body was later found, it had burn marks from a flamethrower, his neighbor said.

Russia’s U.N. ambassador, Vassily Nebenzia, insisted Monday at a news conference that during the time that Bucha was under Russian control, “not a single local person has suffered from any violent action.”

However, high-resolution satellite imagery by commercial provider Maxar Technologies showed that many of the bodies have been lying in the open for weeks, during the time that Russian forces were in Bucha. The New York Times first reported on the satellite images showing the dead.

Western and Ukrainian leaders have accused Russia of war crimes before, and the International Criminal Court’s prosecutor has already opened an investigation. But the latest reports ratcheted up the condemnation.

German Foreign Minister Annalena Baerbock said the images from Bucha reveal the “unbelievable brutality of the Russian leadership and those who follow its propaganda.” And French President Emmanuel Macron said there is “clear evidence of war crimes” in Bucha that demand new punitive measures.

“I’m in favor of a new round of sanctions and in particular on coal and gasoline. We need to act,” he said on France-Inter radio.

Though united in outrage, the European allies appeared split on how to respond. While Poland urged Europe to quickly wean itself off Russian energy, Germany said it would stick with a gradual approach of phasing out coal and oil imports over the next several months.

Russia had withdrawn many of its forces from the capital area after being thwarted in its bid to swiftly capture Kyiv.

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It has instead poured troops and mercenaries into the country’s east in a stepped-up bid to gain control of the Donbas, the largely Russian-speaking industrial region that includes the besieged southern port city of Mariupol, which has seen some of the heaviest fighting and worst suffering of the war.

About two-thirds of the Russian troops around Kyiv have left and are either in Belarus or on their way there, probably getting more supplies and reinforcements, said a senior U.S. defense official who spoke on condition of anonymity to discuss an intelligence assessment.

More than 1,500 civilians were able to escape Mariupol on Monday, using the dwindling number of private vehicles available to get out, Ukrainian Deputy Prime Minister Iryna Vereshchuk said.

But amid the fighting, a Red Cross-accompanied convoy of buses that has been thwarted for days on end in a bid to deliver supplies and evacuate residents was again unable to get inside the city, Vereshchuk said.

Elsewhere, Russian shelling killed 11 people in the southern city of Mykolaiv, regional governor Vitaliy Kim said in a video message on social media.

Zelenskyy appealed for more weaponry as Russia prepares new offensives.

“If we had already got what we needed — all these planes, tanks, artillery, anti-missile and anti-ship weapons — we could have saved thousands of people,” he said.