Palestinian officials say an explosion in the Gaza Strip killed seven people Thursday, while Israeli forces also killed five militants in the territory.

The blast demolished a two-story house belonging to a Hamas commander, Ahmed Hamouda in the town of Beit Lahiya in northern Gaza. The dead include at least two Hamas militants and a baby. The explosion also injured more than 20 other people.

Hamas blamed the Israeli military for the blast and fired about 50 rockets and mortars into southern Israel, wounding an Israeli woman. Israel denied involvement and said the blast may have been caused by militants mishandling explosives.

Israeli forces also killed five militants in separate operations in northern Gaza.

Israeli envoy Amos Gilad visited Cairo Thursday for Egyptian-brokered Gaza truce talks, but later returned to Israel without a deal.

Israeli officials say the envoy reiterated Israel's demands that Hamas release a captive Israeli soldier and that Egypt stop arms smuggling across its border with Gaza. They say Egypt promised to give Israel a response in the coming days.

Earlier, Gaza's Hamas leader Ismail Haniyeh appeared to soften the group's conditions for accepting a cease-fire with Israel.

Haniyeh said Thursday that Hamas would accept a reopening of Gaza's border crossings by Israel at a specified time after a truce begins. Hamas has previously said a truce should begin with Israel easing its blockade of Gaza.

Haniyeh also said an agreement should specify a list of products that Israel will permit to enter Gaza through the border crossings.

Israel has said it could launch a military offensive in Gaza if the truce talks fail.