Israeli Prime Minister Ehud Olmert has expressed regret about the killing of a Palestinian woman and her four children and has vowed to investigate the incident.

Mr. Olmert said at a Cabinet meeting Tuesday that Israel regrets it when civilians are affected by Israeli-Palestinian violence, particularly when it concerns a mother and her four children.

He also said Hamas militants are operating in residential areas in the Gaza Strip and turning Palestinian civilians into an inseparable part of the war.

The incident occurred Monday during fighting between Israeli forces and Palestinian militants in the northern Gaza town of Beit Hanoun.

Palestinians say an Israeli tank shell struck the family's home in Beit Hanoun.  Israel blamed Hamas for the incident and attributed the blast to two Palestinian gunmen whose explosives detonated after an Israeli attack.

Hamas controls the Gaza Strip.

Israeli human rights group B'Tselem has called on the Israeli military to release footage from the aircraft that fired the missile the group says caused the explosion.

Meanwhile, Palestinian factions are in Cairo for Egyptian-mediated talks on a possible truce with Israel.  Factional representatives are due to meet Tuesday with Egyptian intelligence chief Omar Suleiman, a mediator for Israeli-Palestinian talks. 

Some information for this report was provided by AFP, AP and Reuters.