Casualties have continued to pour into hospitals in the Gaza Strip, as the Israeli military presses on with an operation aimed at stopping rocket fire into Israel.
Palestinian health officials say at least 90 people have been killed since Israeli ground forces were sent in on Saturday. More than 500 are said to have been killed since the offensive began.
Twenty-six children were among the dead, the health ministry said, including three young boys whose house was hit by an Israeli shell.
An emergency doctor at Gaza's biggest hospital said many casualties could not be reached because medical workers were being shot at.
Israel says one of its soldiers has been killed and 55 wounded since the ground offensive began. Four other Israelis have been killed in rocket attacks.
Israel says its offensive has substantially reduced the number of rocket attacks. However, another 20 rockets were fired by militants into its territory on Monday.
A BBC correspondent on the Israel-Gaza border says the fighting appears to be concentrated in the north, and Israeli troops appear not to have entered Gaza's most heavily-populated areas.
The UN aid agency in Gaza, Unrwa, said more food was urgently needed, as it had supplies for only another 48 hours. Israel said it had allowed a humanitarian convoy of 80 lorries into Gaza.
Israeli Defence Minister Ehud Barak said Hamas had sustained a very "heavy blow" in the fighting, but that the offensive in Gaza would continue until Israel had met its objectives.
A senior Hamas leader, Mahmoud Zahhar, said in a defiant television address that Israel would be defeated, but could also stop the conflict by ending its blockade of Gaza.