At least 21 Palestinians and three Israelis have died in Gaza's bloodiest day for more than two years.
Palestinians carry a dead youth after he was killed during an Israeli raid at the Jabalya refugee camp in the Gaza Strip
The deaths came during an Israeli incursion ordered after a rocket attack killed two Israeli children in a border town.
In the deadliest single incident, an Israeli tank shell killed seven Palestinians, as Israeli forces thrust deep into Gaza's largest refugee camp for the first time, medical officials said.
Palestinian witnesses said they believed the dead in the tank shell incident in Jabalya camp were all civilians. The Israeli army had no immediate comment.
Earlier today, Palestinian gunmen shot dead two Israeli soldiers and a woman jogger, and Israeli troops in northern Gaza killed 14 people, at least eight of them militants but some civilians. More than 100 people were wounded.
The army's push into Jabalya, a militant stronghold, came after Israeli Prime Minister Ariel Sharon ordered troops to use all means necessary to put a stop to rocket fire that has persisted despite repeated Israeli raids and air strikes.
A Hamas rocket attack on the southern Israeli town of Sderot yesterday killed two Israeli children, aged two and four, as they played outside while visiting their grandparents on the eve of the Jewish harvest festival of Sukkot.
The latest spiral of violence has sent Mr Sharon scrambling to counter rightist critics who say his plan to withdraw troops and settlers from occupied Gaza next year has emboldened militants trying to give the impression that Israel is being driven out.
It was Israel's deepest thrust into Jabalya's narrow alleys in four years of conflict, a move the army had previously avoided for fear that troops and armour would be vulnerable to militant attack.
Mr Sharon plans to meet his security cabinet later today to consider broadening the offensive, political sources said. Radio reports suggested reserves might be called up.
Palestinians condemned the two-day-old Israeli incursion, which intensified this morning when a column of tanks entered the camp and battled scores of armed militants.