Amnesty International said Wednesday it had documented evidence of war crimes by both sides in the conflict between Ukrainian forces and pro-Russian separatists in eastern Ukraine.
The human rights group's secretary general, Salil Shetty, told a news conference in Moscow that some separatists, backed by Russian troops, and Ukraine's Aidar battalion had committed human rights abuses in the five-month-old conflict.
Citing satellite imagery as well as witnesses' accounts, Shetty said Russia's involvement in the violence in eastern Ukraine made it a side in the conflict which could make it liable if war crimes are established.
"We have repeatedly raised the issue of war crimes and in our most recent reports we have documented evidence of war crimes from both sides," said Shetty, repeating the allegations in the Russian capital, where authorities have denied their involvement in the conflict in eastern Ukraine.
Shetty said the organization had requested meetings with Russian President Vladimir Putin and Foreign Minister Sergei Lavrov but neither had agreed to meet him or answered the allegations.
Russia has denied it is a party to the conflict and has dismissed accusations that it has sent soldiers and weapons to support the separatists.
Shetty said human rights abuses, including beatings and abductions, had been carried out by separatists "who we now know have been backed by Russian forces" and by Ukraine's Aidar Battalion, a volunteer territorial defense group.
He also called for an investigation into allegations from both sides of indiscriminate mortar fire, which he said had led to more than 1,000 civilian deaths.