The UN Human Rights Council (UNHRC) has overwhelmingly approved a resolution to set up an investigation into allegations of abuses by Russian troops in areas of Ukraine they temporarily controlled.
The vote on May 12 was 33 members in favor and two countries -- China and Eritrea -- opposed.
Twelve countries abstained from the vote at the Geneva-based council.
The UNHRC's resolution cited apparent cases of torture, shootings, and sexual violence, along with other atrocities documented by a UN team on the ground.
UN High Commissioner for Human Rights Michelle Bachelet, who heads the council, said earlier that thousands of corpses have been found in the region of Kyiv after the retreat of Russian forces in what may be evidence of war crimes.
She said via videolink that authorities were working to verify the violations as Russia's war against Ukraine, which it launched in February, intensifies.
"The scale of unlawful killings, including indications of summary executions in areas to the north of Kyiv, is shocking," Bachelet told the UNHRC as it debates whether to launch an official investigation into what happened when Russian forces moved into the Kyiv region as they looked to take the capital, only to encounter fierce resistance and eventually pull back in early April.
On May 12, the UNHRC condemned atrocities documented by experts in Russian-occupied territories and demanded access for humanitarian workers to people who have been taken from Ukraine to Russia since the invasion began.
It cited allegations that many have been forced to go to Russia.
In the wake of the withdrawal of Russian troops from districts north of Kyiv, officials have been looking at whether civilians were summarily killed or executed by Russian troops, as well as a growing body of evidence pointing to possible rape and sexual violence.
Some of the victims had their hands tied behind their back.
Russian authorities claim that their forces have not attacked civilians in Ukraine and said evidence has been staged in order to justify new Western sanctions against Moscow and to disrupt the peace negotiation process.