"There seems to be a strong possibility that international law has been violated, in a manner that could amount to war crimes," Pillay told an emergency session on Israel's Gaza offensive at the UN Human Rights Council, citing attacks that have killed Palestinian civilians, including children.
She said Israeli children and other civilians also had a right to live without constant fear of rocket attacks.
"Once again, the principles of distinction and precaution are clearly not being observed during such indiscriminate attacks on civilian areas by Hamas and other armed Palestinian groups," she said.