Six killed in bomb-maker's house

An explosion destroyed a Hamas bomb-maker's house in the Gaza Strip on Thursday, killing at least six Palestinians, including a baby, in what Hamas called an Israeli air strike but Israel described as an internal blast.

The explosion, which also wounded some 25 people, came a day after Israel's Security Cabinet decided to give Egypt more time to try to broker a ceasefire under which militants would cease rocket salvoes and Israeli forces would halt Gaza operations.

The blast destroyed the two-storey dwelling and damaged several other homes in the northern Gaza town of Beit Lahiya, an area from which militants frequently launch rockets and mortar shells into southern Israel.

Hamas said an Israeli aircraft attacked the house belonging to Ahmed Hamouda, whom it described as one of its senior bomb-makers.

"The Beit Lahiya massacre was caused by an Israeli strike that targeted a Qassam leader," Hamas said in a statement, referring to its armed wing.

An Israeli military spokeswoman denied any Israeli involvement in the Beit Lahiya explosion and government spokesman Mark Regev said Hamas showed through its response that it was "committed to violence, terror and murder".

In response, Hamas fired over 20 rockets and mortar bombs into southern Israel, injuring one person. Over 40 missiles landed in Israeli territory during the day.

Hamas has long demanded that Israel ease its blockade of the Gaza Strip as a condition of a ceasefire, but in an apparent softening, the group's leader in Gaza, Ismail Haniyeh, said on Thursday it would accept a specified timeline for opening Gaza's border crossings after the truce comes into effect.

Haniyeh said Hamas would need to know "certain dates for the reopening of the crossings".

Israeli officials had no immediate comment but they have argued in the past that opening the crossings would only serve to bolster Hamas.

Medics said at least four Palestinians -- including an infant whose body was held up to television cameras in a hospital -- were killed in the explosion in Beit Lahiya.

Hamouda was not killed but may have been wounded and the bodies of two Hamas gunmen were later found in the rubble.

Major Avital Leibovich, an Israeli army spokeswoman, said: "Our air forces and land forces did not act in that area at that time."

Two Hamas gunmen were wounded in a later Israeli air strike, the group said. An Israeli spokeswoman confirmed the strike and added that troops shot at a vehicle which exploded near the border in the northern Gaza Strip. There were no known casualties.

The Israeli Security Cabinet said on Wednesday it had instructed the military to prepare for a possible broad operation in the Hamas-controlled territory should truce efforts fail.