The Israeli military has continued its air and ground attacks in the Gaza Strip, with troops reported to be moving slowly into the most densely populated areas.
Black smoke was seen rising over the eastern suburbs of Gaza City, where skirmishes were reported between Israeli soldiers and Palestinian militants.
An Israeli army spokeswoman said Israeli troops were advancing more into urban areas, because that was where Hamas militants were mostly hiding.
The Israeli air force has been in action close to the border crossing with Egypt, at Rafah, targeting tunnels used for smuggling.
Palestinian medical officials say nearly 900 people have been killed since the conflict began on 27 December. Israel says 13 Israelis have died, three of them civilians.
The director of emergency services in Gaza, Dr Muawiya Hassanein, said half of the casualties were women and children.
Elsewhere, Palestinian medics and human rights activists accused Israeli forces of illegally firing phosphorus shells at civilian areas, causing serious burns. The Israeli army categorically denied their use.
Militant groups in Gaza have continued to fire rockets into southern Israel, despite the offensive. One caused damage in the city of Ashkelon, although there were no reports of any serious injuries.
Efforts to broker a ceasefire in Gaza have been continuing in Egypt, where the international Middle East envoy, Tony Blair, has held talks with President Hosni Mubarak.
The Israelis say they are close to what they describe as the end game, but say they want to keep up pressure on Hamas as well as exploring a diplomatic way out.