The horror of the discovery is on a par with the Boutcha massacres.
Ukraine claimed on Friday to have found some "450 graves" in Izium, a town recently recaptured from Russian forces in the Kharkiv region in the northeast, a macabre discovery that President Volodymyr Zelensky blamed on "the occupation Russian”.
The Ukrainian president spoke of a "mass grave" on Thursday evening, and the Ukrainian police chief also claims to have unearthed "ten torture rooms" in the Kharkiv region.
"Any information of this nature is shocking," said Elizabeth Throssell, spokeswoman for the High Commission, at the regular UN briefing in Geneva.
She said the UN Human Rights Office wanted to send a team to Izium “soon” to verify the Ukrainian authorities' allegations.
A question already raised during the “siege of Mariupol”
“Our colleagues in Ukraine, from the Human Rights Monitoring Mission in Ukraine, are verifying these allegations and they aim to organize a visit to Izium to determine the circumstances of the death of these people” found in this city.
“They will follow up and hopefully arrange a visit to Izioum soon,” she added.
"It is important that the circumstances of the death of people who may be in these collective graves are established," she said.
When mass graves are discovered, it is important, explained the spokeswoman, to check whether they were soldiers or civilians, whether they were killed or died in the fighting or natural causes exacerbated by lack of medical care.
"As you may recall, this is an issue that was raised many times during the fighting and the siege of Mariupol," she said.
Russia denies having committed all the abuses of which kyiv has accused it since the beginning of the war.
On September 9, the UN reported that its human rights monitoring mission in Ukraine had so far documented more than four hundred arbitrary detentions and enforced disappearances by Russian forces in Ukraine as well as 51 arbitrary arrests by Ukrainian forces.
The mission is to publish a full report on September 27 on the impact of the Russian invasion on human rights in Ukraine.
War in Ukraine: A "mass grave" of 450 graves and ten "torture rooms" discovered in Izium
War in Ukraine: Volodymyr Zelensky visiting Izium, liberated from occupation, and Ursula von der Leyen expected in kyiv
War in Ukraine