Israel killed 60 Palestinians on Saturday in its deadliest and deepest incursion into the Gaza Strip since pulling out in 2005, stoking fears of a broader conflict that could derail renewed US-backed peace talks.
At least 35 of the dead were civilians, among them women and children, said Palestinian doctors who were working round the clock. In all, 87 Palestinians have been killed in four days of air strikes and, now, heavy fighting on the ground in the north.
Two Israeli soldiers were also killed and seven wounded, the army said - its first deaths in Gaza since October. Dozens of Hamas rockets hit Israeli border areas, wounding several people.
As Israeli leaders warned they could step up the assault, a top UN official in Gaza appealed for international action to end the "inhuman suffering" of the people of the enclave.
Palestinian President Mahmoud Abbas, a sworn enemy of Gaza's Islamist rulers, called United Nations Secretary General Ban Ki-moon and asked for an urgent meeting of the UN Security Council to help end the "massacres" in Gaza, an Abbas aide said. Employing a striking phrase used on Friday by a top Israeli official, Abbas said Gazans faced "more than a holocaust".
Israel's deputy defence minister Matan Vilnai, who warned on Friday that Gaza faced a "shoah", said: "As long as events escalate, the chances we will use greater force increases."
With US Secretary of State Condoleezza Rice due to visit next week to promote stuttering peace negotiations between Abbas and Israeli Prime Minister Ehud Olmert, Palestinian negotiator Saeb Erekat warned: "If the Israeli escalation and aggression continue, it will bury the peace process in the rubble." A spokesman for Israel's chief negotiator said: "What Israel is doing in Gaza is fighting terror and it will be continued."
Israel said it was responding to cross-border rockets, which killed an Israeli man in the border town of Sderot on Wednesday and have wounded others in the major southern city of Ashkelon. Meanwhile, Palestinian President Mahmoud Abbas called on Saturday for the United Nations Security Council to hold urgent discussions on the latest round of fighting in the Gaza Strip.
"The president has asked for an urgent session of the Security Council," Abbas spokesman Nabil Abu Rdainah said in a statement, adding that Abbas had already contacted Secretary General Ban Ki-moon on this issue.