In the evening, Egyptian President Hosni Mubarak had announced that it had asked Israelis and Palestinians at an emergency meeting to try to end the war.

The Israeli offensive has killed at least 660 Palestinians and injured more than 2950 since its launch on December 27, according to Palestinian emergency services.

UN agencies and humanitarian organizations have denounced a humanitarian crisis "total" in this poor and overcrowded territory where the population is trapped with no possibility of escape while emergency aid is hampered by the fighting.

The fighting between Palestinian militants and Israeli soldiers continued in Gaza City, in the districts of Zeitoun, Choujaïya Tuffah and at the end of Gaza City, but also in urban areas of north and south.

Three schools run by the UN agency for aid to refugees (UNRWA), where dozens of civilians had fled to escape the fighting, were bombed.

The most deadly attack, carried out in Jabaliya (north), has killed 43 Palestinians, according to Palestinian emergency services. The United Nations, in a statement, reported 30 dead and 55 wounded.

Five other people were killed in attacks against two schools in the United Nations in Gaza and Khan Younis (South), while at least 12 members of the same family clan, including seven children, perished in the bombing of their homes in Gaza, according to medical sources.

Regarding the bombing in Jabaliya, the Israeli government said its forces had responded to shelling from the school. And the army said not to target civilian populations. But, she added, "Hamas has had military installations and arms depots in civilian areas."

The UN Secretary General, Ban Ki-moon has described as "totally unacceptable" attacks against schools, whose locations had been communicated to the Israeli authorities. "

"The attack against the United Nations school shows that war is not against Hamas, but against the entire Palestinian people," said his side the Hamas spokesman, Fawzi Barhoum, whose movement controls Gaza.

The head of UNRWA operations in Gaza John Ging called the situation "horrible tragedy". "Everybody is shocked and terrified because there was no refuge to escape the violence."

"We're dealing with a crisis (...) total of a humanitarian point of view," said a senior official of the International Committee of the Red Cross, Pierre Kraehenbuehl, the offensive has caused a serious shortage of food, fuel and water and electricity cuts.

Despite international calls for a cease-fire, Israel has maintained its refusal to cease operations, supported by its U.S. ally that seeks a "cease-fire, including a cessation of rocket attacks.

"That the acts of terrorism cease, stop arms smuggling from Sinai (Egypt) into Gaza, and Israeli cease fighting," said outgoing Prime Minister Ehud Olmert.

But the 11th day of the attack, 34 rockets have been fired from Gaza on southern Israel, according to the army. One is for the first time fell more than 45 km north-east of the Palestinian territory on Gedera, wounding an infant.

Four Israelis were killed in those shootings since December 27.

In the Gaza Strip, six Israeli soldiers have been killed since the offensive Saturday, including four by "friendly fire".

The army said it killed 130 fighters of Hamas since Saturday.

"We have launched this operation to thrust a blow to Hamas, change the conditions of life in southern Israel, provide calm and security to citizens and stop arms smuggling into Gaza," said Israeli minister of Defense Ehud Barak.

At Sharm el-Sheikh (Egypt), Mr. Mubarak has appealed to both sides to "reach agreements and guarantees" on the Gaza Strip "to stop the current escalation."

Safeguards should include "secure borders", "the opening of border crossing points and lifting the siege" in Gaza, said Mubarak, after a summit with his French counterpart Nicolas Sarkozy.

Mr Sarkozy, who had visited earlier in Damascus and Lebanon, called on Syria to "influence" on its ally Hamas to promote a cessation of hostilities.

Finally, number 2 of Al Qaeda, Ayman Al-Zawahiri, called on Muslims to "address the Israeli and Western interests everywhere" in response to Israel, which he called the offensive " campaign by the West against Islam. " He also accused the U.S. president-elect Barack Obama of "complicity".