Palestinian witnesses said Israeli forces moved into Khan Younis in southern Gaza as the army widened the ground assault it launched four days ago against Hamas militants after a week of air strikes failed to stamp out cross-border rocket fire, Reuters reported.
There was intense fighting overnight on the outskirts of the city of Gaza, where residents huddled indoors in fear. Deaths recorded by Palestinian medics reached 564.
The Israeli army claimed on Tuesday that it has killed 130 Hamas fighters since launching a ground offensive in Gaza at the weekend, as its forces press closer into cities in the Gaza Strip despite new international calls for a ceasefire.
Most of several dozen deaths reported by hospitals in recent days have been civilians, apparently because dead militants remain on the battlefield. The Israeli military said it had killed 130 militants since Saturday -- an indication that the total Palestinian death toll since Dec. 27 may be close to 700.
Israeli strikes hit two separate schools run by the United Nations in the Gaza Strip on Tuesday, killing at least five Palestinians, medics and U.N. officials told AFP.
Two people were killed in a strike on a school in the southern of Khan Yunis and three people were killed in an air strike on a school in Gaza City, the report said. Both schools are run by UNRWA, the U.N. agency for Palestinian refugees.
Israel poured ground forces into Gaza late Saturday, a week after unleashing a massive air and naval bombing campaign against Hamas targets in the enclave aiming to stop rocket fire.


French President Nicolas Sarkozy, on a peace mission to the Middle East, and U.S. President George W. Bush, in his final weeks in the White House, both appealed for a ceasefire.

But disagreement on who should stop shooting first and on what terms made the chances of a quick truce seem remote.

Turkish Foreign Minister Ali Babacan left for New York late on Monday to discuss the recent situation in Gaza in a meeting which will take place in U.N. Security Council, after attending a meeting with Turkish President Abdullah Gul and Prime Minister Tayyip Erdogan in Ankara.
It was decided in the meeting that Babacan would visit New York to attend a meeting at the United Nations and Ahmet Davutoglu, chief adviser to Prime Minister Erdogan, would travel to Damascus to hold talks upon a demand from French President Nicolas Sarkozy who would also visit Syria, a statement released by the Presidential Press Center said after the meeting.
The statement said Erdogan's tour to four countries in the Middle East as well as talks held by Gul and the Turkish prime minister in phone conversations with authorities in the region and Europe were to be discussed in the meeting.
Efforts would be intensified for transfer of humanitarian aid to the people in Gaza, it added