Both Israel and Palestinian forces committed "serious violations" of international law and possible war crimes in last summer's seven-week Gaza war, a new report from the United Nations charges.

The U.N. Independent Commission of Inquiry said that "substantial information" and "credible allegations" indicate that both sides committed war crimes during the conflict, which left more than 2,200 Palestinians dead and 11,000 injured, and 73 Israelis dead.

"In the 51 day operation, 1,462 Palestinian civilians were killed, a third of them children. Palestinian armed groups fired 4,881 rockets and 1,753 mortars towards Israel in July and August 2014, killing 6 civilians and injuring at least 1,600," the report said.

"The extent of the devastation and human suffering in Gaza was unprecedented and will impact generations to come," said commission chair, New York judge Mary McGowan Davis, according to the Guardian.

The report, commissioned by the U.N. Human Rights Council, says that Israeli and Palestinian leaders should have known that their failure to change course as the war progressed would result in a large number of civilian casualties.

"Those responsible for suspected violations of international law at all levels of the political and military establishments must be brought to justice," the report said.

The report laid most of the blame on Israel, specifically decrying the "huge firepower" Israel used in Gaza, conducting more than 6,000 airstrikes and firing 50,000 artillery shells during the 51-day fight. Israel refused to cooperate with the inquiry, according to the Guardian.

The commission asked Israel to "break with its recent lamentable track record" and hold wrongdoers accountable, but also criticized Palestinian militants for "inherently indiscriminate nature" of rocket and mortar attacks.

Israel fired back Monday, with its ambassador to the U.N., Ron Prosor, calling the report biased and claiming that the "U.N. has been taken hostage by terrorist organizations," reported Fox News.

"Any comparison between IDF soldiers who seek to defend innocent civilians, and the terrorists who indiscriminately target Israelis while deliberately endangering Palestinians is completely unacceptable," he said, according to Fox.

Israeli Prime Minister Benjamin Netanyahu added that Israel "does not commit war crimes," reported AFP.

Fawzi Barhum, a spokesman for Hamas, welcomed the report's "condemnation of the Zionist occupier for its war crimes during the last war against Gaza," but didn't address the report's allegations regarding Palestinian militants, reported AFP.