Undercover Israeli troops burst into a West Bank vegetable market today killing four Palestinians.
Troops exchanged heavy fire with Palestinian gunmen in the first major raid since the Israeli and Palestinian leaders agreed to try to ease tensions between the sides.
Four Palestinians, all civilians, were killed and 20 wounded in the fighting. Palestinian president Mahmoud Abbas said in a harshly worded statement that Israel's peace promises rang hollow in light of the raid and demanded compensation for the damage to shops and cars in Ramallah.
The raid came as plans were revealed for US Secretary of State Condoleezza Rice to visit the Middle East this month to try to promote peacemaking.
Ms Rice will travel to try to promote peacemaking, senior European diplomat Javier Solana said after they met today.
Asked if Ms Rice was optimistic about prospects for peacemaking between Israel and the Palestinians, Solana told reporters: "I don't think that optimism is the word. We have to stick to the word realism." In Gaza, six Palestinians, including a senior security officer, were killed today and more than a dozen wounded in a new wave of fighting between gunmen loyal to Hamas and those allied with Abbas.
Israeli prime minister Ehud Olmert, who met with Egyptian president Hosni Mubarak just a few hours after the Ramallah raid, apologised for any civilian casualties, but said the raid was intended to protect Israel from terrorist attacks.
"Things developed in a way that could not have been predicted in advance. If innocent people were hurt, this was not our intention," he said.
The summit had been intended to push for new Israeli-Palestinian peace efforts, but was overshadowed by the violence.
Standing next to Mr Olmert in the Red Sea resort of Sharm El-Sheikh, Mr Mubarak condemned the raid. "Israel's security cannot be achieved through military force but by serious endeavours toward peace," he said.
Mr Abbas said Israel's assurances that it is striving for peace and security cannot be believed. "The continued aggression will only lead to the destruction of all efforts aimed at realising peace," the statement said.
In the northern Gaza Strip, a senior Palestinian security officer allied with Fatah was killed when Hamas militants laid siege to his house, engaging in a protracted gunbattle with his guards, and then attacked it with grenades and a dozen rockets, Palestinian officials and witnesses said.
The officer, Col Mohammed Ghayeb, was the chief of the Preventive Security Service in northern Gaza, and his killing was expected to trigger revenge attacks by the men under his command.
Ms Rice reviewed her plans at the State Department with Mr Solana, the senior European Union diplomat who will make his own, separate trip to the area this month. They also had lunch at the White House with Stephen Hadley, US President George Bush's national security adviser.
"We will try to see how we can give a push to the peace process," Mr Solana said. He declined to say whether Rice would try to set up a peace conference. Ms Rice did not take questions from reporters while posing for pictures with Mr Solana in her office.
However, US State Department spokesman Sean McCormack was optimistic about her making headway. "The way she sees it is that there is a potential opening here to make progress on the issues of a two-state solution, Israel and Palestine living side by side in peace and security," Mr McCormack said.