AFP - Israel blasted a harsh UN report on its three-week war on Gaza that is to be submitted to the Security Council on Tuesday, branding it biased toward the Islamist group Hamas and misleading.

The UN report says the Israeli military intentionally fired at UN facilities and civilians hiding in them during the massive offensive in December-January against the Hamas rulers of Gaza, media reports said.

"The state of Israel rejects the criticism in the committee's summary report, and determines that in both spirit and language, the report is tendentious, patently biased, and ignores the facts presented to the committee," the foreign ministry said in a statement.

"The committee has preferred the claims of Hamas, a murderous terror organisation, and by doing so has misled the world."

The report is the latest criticism of Israel over the 22-day war it launched against the Hamas-run territory on December 27 in response to ongoing rocket fire from Gaza militants.

The war, which ended with Israel and Hamas declaring ceasefires on January 18, killed more than 1,400 Palestinians and 13 Israelis and left large swathes of the impoverished territory in ruins.

Several UN buildings, including its headquarters in Gaza, and several UN-run schools, were hit by Israeli fire during the offensive.

The foreign ministry said that despite Israel cooperating fully with the committee and presenting it with various intelligence material, "none of this information is reflected in the report."

"The report completely ignores the eight years of attacks against Israel that preceded the decision to initiate the operation, and ignores the difficult circumstances on the ground as dictated by Hamas and its methods of armed operation" from within heavily-populated civilian areas, it said.

"The UN is responsible for drawing its own conclusions regarding the means it should implement to contend with the complex reality in which a terror organisation operates in proximity to UN installations without differentiation and in a manner that endangers UN activities," said the ministry statement.

"We expect clear statements and action from the UN in this regard," it said.

UN chief Ban Ki-moon received a copy of the report several days ago and has since softened some of the wording in the three-page document, which he is due to submit to the Security Council on Tuesday, wrote the Ynet news website.

But Israeli officials are worried that the current wording is still too critical towards the Jewish state, the mass-selling Yediot Aharonot said.

The newspaper quoted a member of the US delegation at the United Nations as saying the report was "unprecedented in its gravity towards Israel, and Israel will have to lick the wounds of the report for many years, if the current wording is accepted as is."

The report, authored by a special committee led by a former head of Amnesty International, Ian Martin, contains several serious charges against Israeli forces.

"Israel deliberately fired at UN institutions even though it knew it was forbidden," wrote the Yediot.

"The report accuses Israel of disproportionate fire and excessive use of force. The report also states that Israel shot at Palestinian civilians unnecessarily and excessively."