President Volodymyr Zelensky said on Thursday that Ukrainian authorities found a mass grave in Izyum after the northeastern town was retaken from Russian forces.
"We want the world to know what the Russian occupation has caused," he said, without giving details on the number of bodies found or their cause of death.
"We need to have more clear and verified information tomorrow."
A regional police official, Sergei Botvinov, told Sky News that a burial site with around 440 graves had been discovered in Izyum.
Some of the dead were shot, others died in shelling, he added.
Zelensky compared Izyum to the cities of Bucha and Mariupol which have become symbols of atrocities during the Russian invasion of Ukraine.
"Russia leaves death behind everywhere. And she must respond. The world must really hold Russia responsible for this war. We are going to do everything we can to do that," he said.
On Wednesday, Zelensky made a rare trip outside the capital to watch the national flag being raised over Izium’s city hall.
Deputy Interior Minister Yevhen Enin said Thursday night that other evidence found after Kyiv’s sweeping advance into the Kharkiv region included multiple “torture chambers” where both Ukrainian citizens and foreigners were detained “in completely inhuman conditions.”
“We have already come across the exhumation of individual bodies, not only with traces of a 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.
