GENEVA — Nearly 300 people were killed since Oct. 18 in fighting which continues in eastern Ukraine despite a cease-fire agreement, United Nations human rights investigators said Thursday.

A new report from the U.N. monitoring team in Ukraine said at least 4,317 people have been killed — up from the 4,042 deaths reported in October — from mid-April until Nov. 18.

The number of internally displaced people has sharply increased to 466,829, compared to 275,489 as of Sept. 18, the report said.

Russia, meanwhile, reacted sharply to a U.S. official's comment that Washington should consider supplying weapons to Ukraine.

"We repeatedly heard confirmations from the (U.S.) administration that only non-lethal weapons would be delivered to Ukraine. If there is a change in this policy, then this is a highly destabilizing factor that could seriously influence the balance of power in the region," said Alexander Lukashevich, spokesman for the Russian Foreign Ministry.

Tony Blinken, the deputy national security adviser, told a U.S. Senate committee on Wednesday that strengthening Ukraine's forces is "something we should be looking at."

The Obama administration has resisted supplying arms to Ukraine, although there is broad support in Congress for doing so.

The report released by the U.N. human rights office in Geneva cited allegations of serious human rights abuses by armed groups including torture, detention, executions, forced labor and sexual violence that "are of a systematic nature and may amount to crimes against humanity."

It says the standoff between government troops and pro-Russian rebels battling in eastern Ukraine "is becoming increasingly entrenched, with the total breakdown of law and order and the emergence of parallel governance systems" in Donetsk, the largest city under separatist control, and in the rebel-controlled section of the Luhansk region.

The report warned that treatment for almost 60,000 HIV-positive patients and 11,600 multi-drug resistant tuberculosis patients could be disrupted by a lack of medicine, which "may lead to the uncontrolled spread of epidemics."

"Respect for the cease-fire has been sporadic at best, with continued outbreaks of fighting and shelling resulting in an average of 13 people a day being killed during the first eight weeks of the cease-fire," U.N. High Commissioner for Human Rights Zeid Raad al-Hussein said in a statement.

"All parties need to make a far more wholehearted effort to resolve this protracted crisis peacefully and in line with international human rights laws and standards."

Laura Mills in Moscow contributed to this report.