The United Nations said on Friday that its investigators have found evidence of war crimes committed by Russian forces in Ukraine.

"Based on the evidence gathered by the Commission, it has concluded that war crimes have been committed in Ukraine," the Commission of Inquiry chief told the UN Human Rights Council.

The commission was set up in May to investigate claims of war crimes. They have so far focused on four regions: Kyiv, Kharkiv, Sumy and Chernihiv.

"We were struck by the large number of executions in the areas that we visited. The commission is currently investigating such deaths in 16 towns and settlements,'' said Erik Mose, the commission's chairman.

"This is of course a novel incident but we certainly intend to look into the Izium event as well," he said, referring to the city in eastern Ukraine where hundreds of bodies have been uncovered. According to Ukrainian officials, 436 bodies were exhumed from a mass burial site near the recently liberated city. 

"Most of them have signs of violent death, and 30 have signs of torture. There are bodies with rope around their necks, with their hands tied, with broken limbs and gunshot wounds," said Kharkiv regional governor Oleg Synegubov.

Asked about whether crimes against humanity had been committed, Mose said the commission had not yet come to that conclusion.

How were the investigations carried out?

The UN investigators spoke with over 150 victims and witnesses and visited 27 towns and settlements where they also investigated graves as well as detention and torture centers.

The team also looked into two cases of mistreatment of Russians by Ukrainian soldiers.

"Tomorrow will mark seven months since the outset of the hostilities in Ukraine," the commission said in a statement. "We are concerned by the suffering that the international armed conflict in Ukraine has imposed on the civilian population."

"This is illustrated by the figures updated regularly by the [Office of the Commissioner for Human Rights (OHCHR)] concerning deaths and injuries and by the [UN High Commission for Refugees] with respect to refugees and internally displaced persons," the statement added. "The recent discovery of yet additional graves illustrates the gravity of the situation."

What did the UN commission find in Ukraine?

The commission's report highlighted several areas where Russian activities had been particularly harmful, including general, indiscriminate attacks on civilian areas, executions, torture and sexual and gender-based violence.

The commission reported that Russia's "use of explosive weapons with wide area effects in populated areas is a source of immense harm and suffering for civilians," and that a number of attacks "had been carried out without distinguishing between civilians and combatants," including with the use of "cluster munitions or multi-launch rocket systems and airstrikes in populated areas."

The statement cited 16 towns and settlements where there are ongoing investigations into executions, with "credible allegations" of many more cases.

There were "consistent accounts of ill-treatment and torture" from Ukrainian victims, some of whom said they had been moved to detention centers in Russia where they had been held for weeks. Some victims have reportedly disappeared.

The commission also presented testimonies of beatings, electric shocks and forced nudity by former detainees in Russian detention centers.

Commission chairman Mose also said they had found evidence of an unspecified number of Russian soldiers who had committed crimes of sexual or gender-based violence. Their victims' ages ranged from 4 to 82 years old.

"The Commission has documented cases in which children have been raped, tortured, and unlawfully confined," the statement said.

jsi, ab/kb (AP, AFP, Reuters)