In Izyum, a city retaken from the Russians a few days ago as part of a Ukrainian counteroffensive in the east of Kharkiv region, a “mass burial” was discovered, President of Ukraine Volodymyr Zelenskyi said on Thursday evening, AFP reports.

“We want the world to know what the Russian occupation caused,” he said, without giving details about the number of people buried or the cause of their deaths. The investigation has been launched, “tomorrow we should have more verified and clear information,” Zelensky added in a daily video message.

Regional police chief Serhii Botvinov told Sky News that a burial ground with about 440 graves was discovered in Izyum.

Some of the dead were shot, others died during the bombings, he added.

For his part, Zelenskyi compared Izyum with the cities of Bucha and Mariupol, which became symbols of the atrocities of the Russian invasion of Ukraine.

“Russia is leaving behind death everywhere. And it must respond. The world must hold Russia accountable for this war. We will do everything possible for this,” he said.