The United Nations warned Friday of an "alarming deterioration" of human rights in eastern Ukraine, prompting Russia to respond and describe the report as doubled standards.

The United Nations warned Friday of an "alarming deterioration" of human rights in eastern Ukraine, prompting Russia to respond and describe the report as doubled standards.

In a new report, UN High Commissioner for Human Rights Navi Pillay voiced deep concern about "serious problems" of harassment and intimidation facing the Tatar community in Crimea, which was annexed by Russia in March in the face of international outrage.

The report catalogues a litany of "targeted killings, torture and beatings, abductions, intimidation and some cases of sexual harassment" which it said was carried out by anti-government groups in the east of Ukraine.

In a veiled reference to Russia, Pillay called on "those with influence on the armed groups responsible for much of the violence in eastern Ukraine to do their utmost to rein in these men who seem bent on tearing the country apart".

For its part, Russia dismissed the UN report as biased and politically motivated.

"The complete lack of objectivity, blatant discrepancies and double standards leave no doubts that (the report's) authors were performing a political put-up job aimed at clearing the name of the self-declared authorities in Kiev," the Russian foreign ministry said in a statement.