President Volodymyr Zelenskyy says Ukrainian authorities have found a mass burial site near a recently recaptured northeastern city previously occupied by Russian forces.
"A mass grave of people was found in Izium in the Kharkiv region. The necessary procedures have already begun there. More information - clear, verifiable information - should be available tomorrow," Zelenskyy said in his nightly televised address.
Associated Press journalists saw the site in a forest near Izium on Thursday. A mass grave bore a marker saying it contained the bodies of 17 Ukrainian soldiers. It was surrounded by hundreds of individual graves with only crosses to mark them.
Zelenskyy invoked the names of other Ukrainian cities where authorities said retreating Russian troops left behind mass civilian graves and evidence of alleged war crimes.
"Bucha, Mariupol, now, unfortunately, Izium ... Russia leaves death everywhere. And it must be held accountable for it. The world must bring Russia to real responsibility for this war," he said.
Russia's forces left Izium and other parts of the Kharkiv region last week amid a stunning Ukrainian counteroffensive. On Wednesday, Zelenskyy made a rare trip outside Ukraine's capital to watch the raising of the national flag at Izium's city hall.
Ukraine's deputy interior minister, Yevhen Enin, said on Thursday night that evidence of the occupying Russian troops setting up multiple "torture chambers" where both Ukrainian citizens and foreigners were detained "in completely inhuman conditions" was found in cities and towns recaptured during Kyiv's sweeping advance into the Kharkiv region.
"We have already come across the exhumation of individual bodies, not only with traces of violent death but also of torture - cut-off ears, etc. This is just the beginning," Enin said in an interview with Ukraine's Radio NV. His description matched at least half a dozen reports made by Kharkiv regional police representatives since last weekend.
He claimed that among those held at one of the sites were students from an unspecified Asian country who were captured at a Russian checkpoint as they tried to leave for Ukrainian-controlled territory.
Enin did not specify where the students were held, although he named the small cities of Balakliya and Volchansk as two locations where the alleged torture chambers were found. His account could not be immediately verified independently.
"All these traces of war crimes are now carefully documented by us. And we know from the experience of Bucha that the worst crimes can only be exposed over time," Enin said, in a reference to a Kyiv suburb where the bodies of hundreds of civilians were discovered following the Russian army's withdrawal from the area in March.
Earlier on Thursday, Zelenskyy said during the five months the Russians occupied the region, they "only destroyed, only deprived, only took away. They left behind devastated villages; in some of them, there is not a single undamaged house. The occupiers turned schools into garbage dumps, and churches - shattered, literally turned into toilets".