Israel's prime minister says the United Nations report on the 2014 Gaza war is "biased".
Binyamin Netanyahu said the UN Human Rights Council, which commissioned the inquiry, does "everything but worry about human rights".
The report found that both Israel and Palestinian militant groups may have committed war crimes during the conflict last July.
More than 2,200 Palestinians, including hundreds of civilians, were killed during the fighting, according to UN and Palestinian officials - while 73 people, including six civilians, died on the Israeli side.
Mr Netanyahu insisted that Israel acted throughout the conflict according to international law.
Gaza’s Hamas rulers also rejected the claims in the United Nations report.
Senior Hamas official Ghazi Hamad said that its rockets and mortars were aimed at Israeli military sites, not at civilians.
Mr Hamad criticised the UN investigators for what he said was a false balance between victims and killers.
Military onslaught
The report accused Israel of failing to alter the course of its military onslaught when the extent of the killing of Palestinian civilians became clear.
The panel said the indiscriminate firing of missiles into Israel by Palestinian armed groups in the Hamas-ruled territory may constitute a war crime.
The execution without trial of alleged Palestinian collaborators with Israel amounts to a war crime, it said.
“The commission was able to gather substantial information pointing to serious violations of international humanitarian law and international human rights law by Israel and by Palestinian armed groups,” said the report issued from Geneva.
“In some cases, these violations may amount to war crimes.”
Israel refused to cooperate with the commission, saying it was biased, and issued its own report last week asserting military forces complied with international law.
The UN panel called on both Israelis and Palestinians to cooperate with a further investigation by the International Criminal Court, which may yield a war crimes trial.
Reuters/Bloomberg