On average 13 people have been killed each day during the first eight weeks of the September 5 ceasefire, with a total of 957 deaths recorded up to November 18th, the UN rights agency said.
The number of people registered as displaced within Ukraine soared from 275,489 in mid-September to 466,829 on Wednesday, it added.
"The list of victims keeps growing. Civilians, including women, children, minorities and a range of vulnerable individuals and groups continue to suffer the consequences of the political stalemate in Ukraine," UN rights chief Zeid Ra'ad Al Hussein said in a statement.
Counting the 298 people who died in the downing of Malaysian Airlines flight MH17 over Ukraine in July, the overall toll since mid-April stands at 4,317 deaths as of Tuesday, the UN rights office said.
Nearly 1,200 of those killed were Ukrainian troops, while more than 1,700 civilians and members of armed groups had been killed in Donetsk, including 22 children, and more than 850 civilians and rebels had been killed in Lugansk, including 14 children, the report said.
In all, 9,921 have been injured in the conflict-hit area of eastern Ukraine, the report said.
This is "a conservative estimate", the report said, adding that "the actual number of fatalities may be much higher."
In their seventh report, the 35-strong UN Human Rights Monitoring Mission in Ukraine described "the total breakdown of law and order."
They warned that an influx of sophisticated weapons and foreign fighters, including Russian troops, was having a devastating impact on the human rights situation in the country.