Intense diplomatic efforts were under way to try to secure a ceasefire in Gaza on Monday, as the Israeli assault against Hamas entered its 10th day.
The United Nations' Middle East envoy was recalled to New York for briefings and Hamas said it was sending a delegation to Egypt for talks.
Separate missions to the Middle East are being led by the French president, Nicholas Sarkoy, and a high-level team from the European Union.
Israeli troops pushed deeper into Gaza, with reports by unnamed Palestinian sources of Israeli tanks moving towards the southern town of Khan Younis.
Earlier, Israeli forces took up positions in the north on either side of Gaza City, effectively cutting Gaza into two parts, from the Karni crossing to the Mediterranean Sea.
Palestinians said Israeli forces had killed seven members of a Palestinian family in a strike on their home. They said the attack at Beach refugee camp, on the outskirts of Gaza City, followed a separate shelling that killed three children and their mother.
More than 500 Palestinians are reported to have been killed so far.
Hamas officials say 10 of its fighters have so far been killed in the ground offensive, while the Israeli military reports one of its soldiers dead and 34 wounded.
The invasion began on Saturday night after a week of Israeli bombardments since 27 December. The attacks started after Hamas ended a truce on 19 December.