The UN's top human rights official has backed a report accusing Israeli forces and Palestinian militants of war crimes during their conflict in Gaza last winter. Navi Pillay's endorsement of the report by an expert group led by Judge Richard Goldstone came as Israel warned the UN Human Rights Council that approving the document risked undermining Middle East peace. Pillay told the 47-member council that she supported the report's recommendations, including its call for urgent action to counter impunity, meaning that Israel and Hamas must investigate and prosecute those who committed war crimes. The 575-page report concluded that Israel used disproportionate force, deliberately targeted civilians, usedPalestinians as human shields, and destroyed civilian infrastructure during its Dec 27- Jan 18 incursion into theGaza Strip to root out Palestinian rocket squads. Almost 1,400 Palestinians and 13 Israelis were killed during the three-week conflict.