A climate of “pervasive impunity” in eastern Ukraine has meant very few people have been held accountable for a catalogue of alleged summary executions, the UN says.
The Office of the High Commissioner for Human Rights (OHCHR) says some of the cases could amount to war crimes.
It investigated the disappearances and deaths of at least 47 people in areas held by Russian-backed separatists.
The report also lists 29 cases in government-controlled territory.
Almost 9,500 people have died in eastern Ukraine since conflict broke out in 2014. Pro-Russian rebels seized swathes of Ukraine’s eastern regions of Donetsk and Luhansk, after Russia annexed the Ukrainian peninsula of Crimea, weeks after the ousting of Ukraine’s President, Viktor Yanukovych.
In one case the OHCHR obtained forensic evidence showing that a six-year-old girl, her mother and her grandmother were killed by gunshots to the head in the rebel-held region of Luhansk.