The UN human rights office in Ukraine has registered 3,381 civilian deaths in the country since the beginning of the Russian invasion, with some 1,000 in the besieged port city of Mariupol alone.
The security situation has so far not allowed the cases to be documented individually and actual figures are expected to be much higher.
“We are working to corroborate every single incident,” said Matilda Bogner, head of the commission that has been investigating the human rights situation in Ukraine since 2014.
She said her team, with almost 60 experts, has documented numerous human rights violations since Russia invaded Ukraine.
“Many of these allegations concern violations that may amount to war crimes.
“People told us of relatives, neighbours and friends killed, injured, detained and disappeared,” she said.
Mrs Bogner said that at least 204 people were abducted, including 169 men, 34 women and one boy.
The perpetrators were almost exclusively Russian soldiers and affiliated armed groups in eastern Ukraine.