The Islamist Hamas movement said Wednesday it has investigated allegations in a UN report into last winter's Gaza war and absolved Palestinian armed groups of any atrocities.

The UN Human Rights Council report authored by the respected former international prosecutor Richard Goldstone accused both Israel and Palestinian groups of war crimes during the devastating 22-day conflict.

Some 1,400 Palestinians and 13 Israelis were killed during the Israeli offensive aimed at halting rocket attacks from the territory ruled by the Islamist militant group, which is sworn to the destruction of the Jewish state.

But Hamas, which along with other armed groups has launched thousands of makeshift rockets into southern Israel in recent years, said a committee it appointed to follow up on the report found no intention to harm civilians.

"The committee worked around the clock to uncover the facts, despite the certainty that there were no violations of international humanitarian law or international human rights law that amount to war crimes," said the committee head, Hamas justice minister Mohammed Faraj al-Ghul.

"The Palestinian government has on more than one occasion called on armed Palestinian groups to avoid targeting civilians," said the report by Hamas, which has claimed scores of deadly suicide bombings against Israeli civilians.

"(The armed groups) struck military targets and avoided civilian targets, and any accusations related to this concern errant fire."

The Goldstone report said the firing of the hard-to-aim rockets at southern Israel deliberately targeted civilians and could constitute a crime against humanity.

The Goldstone report recommended its findings be referred to the International Criminal Court in the Hague if Israel and Hamas failed to carry out credible, independent investigations.

Israel has rejected the report as "anti-Semitic" despite the fact Goldstone is Jewish, because the report accuses Israeli troops of deliberately targeting civilians and destroying vital infrastructure.