NEW YORK — Russian and Western diplomats clashed over alleged war crimes in Ukraine on Thursday during a heated meeting of the U.N. Security Council.

Secretary of State Antony Blinken said Russia’s withdrawal from the Ukrainian cities of Izium and Bucha revealed gruesome torture and murder of Ukrainian civilians that could not be dismissed as the actions of a few bad actors.

“Wherever the Russian tide recedes, we discover the horror that’s left in its wake,” Blinken said. “We cannot, we will not allow President Putin to get away with it.”

Russian Foreign Minister Sergei Lavrov denied the charges and accused Ukrainian forces of killing civilians in the eastern Donbas region “with impunity.”

He accused the United States, France and Germany of not holding Ukraine accountable for alleged atrocities.

“The Kyiv regime owes its impunity to its Western sponsors,” he said.

The meeting marked only the second encounter between Blinken and Lavrov since Russia’s Feb. 24 invasion of Ukraine. Moscow’s decision to attend the meeting surprised some U.S. officials who expected Russia to recoil at a topic designed to expose and condemn its plans to stage a referendum and annex occupied territory in Ukraine.

In singling out Russia for blame, Blinken was joined by top diplomats representing France, Britain, Norway, Albania and Ireland, as well as U.N. Secretary General António Guterres, who accused the Kremlin of violating international law.

The meeting was attended by the chief prosecutor of the International Criminal Court, Karim Khan, who said his team was deploying to Ukraine in the coming days to investigate allegations in the country’s east, where residents of territory previously occupied by Russia have accused Russian forces of torture, forced disappearances and rape.

Without explicitly blaming Russia, Khan made clear the atrocities he has investigated during visits to war-scorched areas of Ukraine including the Kyiv suburb of Bucha and the northeastern city of Kharkiv were real and shocking.

“The bodies I saw were not fake,” he said.

French Foreign Minister Catherine Colonna said that Russia has committed “unspeakable crimes” and that officials who committed, ordered or planned them must be held accountable.

Guterres called Moscow’s plan to stage referendums on joining Russia in occupied areas of Ukraine a “violation of the U.N. charter and of international law and precedent.”

The world’s top diplomat also blamed Russian bombardments of urban areas for killing thousands of Ukrainian civilians, including hundreds of children.

“Almost every child in Ukraine has been scarred by the nightmare of war,” he said.

Chinese Foreign Minister Wang Yi urged restraint on both sides and emphasized the importance of the United Nations remaining impartial in the conflict.

India’s top diplomat, Subrahmanyam Jaishankar, also avoided placing blame on either Russia or Ukraine, simply endorsing investigations of war crimes.​