JERUSALEM (Reuters) - Israel issued a report on Sunday arguing its 2014 Gaza offensive was lawful, a move aimed at pre-empting the release of findings of a U.N. war crimes investigation that Prime Minister Benjamin Netanyahu scorned as a waste of time.

A Palestinian boy walks up the stairs inside the ruins of their house, that witnesses said was destroyed during a seven-week Israeli offensive, in the east of Gaza City October 19, 2014. REUTERS/Mohammed Salem

The 277-page report, which cited Israel’s internal probes and statements from Western leaders backing its right to self-defense, suggested the Netanyahu government hoped to defuse criticism from the U.N. Human Rights Council (HRC) inquiry in advance.

Deeming the HRC biased, Israel boycotted its investigators as it did those from the council who looked into its 2008-09 Gaza offensive. That HRC inquiry accused Israel of war crimes.

Launched last July after a surge of cross-border rocket fire by Hamas and other Palestinian armed groups, Israel’s 50 days of shelling, air strikes and ground incursions in the congested enclave killed more than 2,256 Palestinians, including 1,563 civilians, a U.N. report said in March.

Sixty-seven Israeli soldiers and six civilians in Israel also died in the conflict.

The new Israeli government report disputed the U.N. figures, saying confirmed non-combatants made up 36 percent of the Palestinian dead and many militants were misidentified as civilians.

“Harm to the civilian population also occurred as the result of unfortunate -- yet lawful -- incidental effects of legitimate

military action in the vicinity of civilians and their surroundings, and as a result of the inescapable constraint of commanders not being infallible, intelligence not being perfect and technological systems sometimes failing,” the document said.

In public remarks to his cabinet, Netanyahu again accused Hamas of hiding behind civilians by deliberately operating in Gaza’s crowded districts.

“Whoever wants to continue with baseless blaming of the State of Israel, let them waste time reading the report by the U.N. commission. We, for our part, will continue protecting our soldiers. They will continue protecting us,” he said.

The HRC inquiry into possible war crimes by Israel and Hamas, an Islamist group that controls Gaza, is due to publish its findings this week, diplomats said, having postponed the release from March to consider further evidence.

Hamas spokesman Sami Abu Zuhri called the Israeli report worthless, saying “Israeli war crimes are clear because they were committed in front of live cameras”. Hamas has denied any wrongdoing, saying it acted to protect Palestinians.

The HRC’s former chief Gaza investigator, William Schabas, resigned in February over consultancy work he previously did for the Palestine Liberation Organization.