As Zelenskyy spoke to the diplomats, survivors of the monthlong Russian occupation showed investigators bodies of townspeople allegedly shot by Russian troops.

Police and other investigators walked the still largely empty streets of Bucha, where dogs wandered among ruined buildings and burned military vehicles. Officials snapped photos of the corpses before gathering up some of them.

Survivors who hid in their homes during the occupation, many of them beyond middle age, wandered past charred tanks and jagged window panes with plastic bags of food and other humanitarian aid. Red Cross workers checked in on intact homes.

Associated Press journalists in Bucha have counted dozens of corpses in civilian clothes and interviewed Ukrainians who told of witnessing atrocities. Also, high-resolution satellite imagery from Maxar Technologies showed that many of the bodies had been lying in the open for weeks, during the time that Russian forces were in the town.

The dead in Bucha included a pile of six charred bodies, as witnessed by AP journalists. It was not clear who they were or under what circumstances they died. One body was probably that of a child, said Andrii Nebytov, head of police in the Kyiv region.

Many of the dead seen by AP journalists appeared to have been shot at close range, and some had their hands bound or their flesh burned.

The AP and the PBS series “Frontline” have jointly verified at least 90 incidents during the war that appear to violate international law. The War Crimes Watch Ukraine project is looking into apparent targeted attacks as well as indiscriminate ones.

U.S. Secretary of State Antony Blinken said the images from Bucha revealed “not the random act of a rogue unit” but “a deliberate campaign to kill, to torture, to rape, to commit atrocities.” He said the reports of atrocities were “more than credible.”

“Only non-humans are capable of this,” said Angelica Chernomor, a refugee from Kyiv who crossed into Poland with her two children and saw the photos from Bucha. “Even if people live under a totalitarian regime, they must retain feelings, dignity, but they do not.”

Chernomor is among the more than 4 million Ukrainians who have fled the country in the wake of the Feb. 24 invasion.

Russia has rejected similar accusations of atrocities in the past by accusing its enemies of forging photos and video and using so-called crisis actors.

The chief prosecutor for the International Criminal Court at The Hague opened an investigation a month ago into possible war crimes in Ukraine.

Elsewhere in Ukraine, in Borodyanka, northwest of Kyiv, a 25-year-old, Dmitriy Yevtushkov, searched the rubble of apartment buildings and found that only a photo album remained from his family’s home.

In the besieged southern city of Mykolaiv, a passerby stopped briefly to look at the bright blossoms of a shattered flower stand lying among bloodstains, the legacy of a Russian shell that killed nine in the center of the city earlier this week. The onlooker sketched out the sign of the cross in the air, and moved on.

NATO Secretary-General Jens Stoltenberg, meanwhile, warned that in pulling back from the capital, Russian President Vladimir Putin’s military is regrouping its forces in order to deploy them to eastern and southern Ukraine for a “crucial phase of the war.” Russia’s stated goal currently is control of the Donbas, the largely Russian-speaking industrial region in the east that includes the shattered port city of Mariupol.

“Moscow is not giving up its ambitions in Ukraine,” Stoltenberg said.

While both Ukrainian and Russian representatives sent optimistic signals following their latest round of talks a week ago, Russian Foreign Minister Sergey Lavrov said Moscow will not accept a Ukrainian demand that a prospective peace deal include an immediate pullout of troops followed by a Ukrainian referendum on the agreement.