At least 140 Palestinians, most of them Hamas security members, were killed before Saturday noon when Israeli airplanes launched simultaneous strikes across the Gaza Strip, said medical sources.

Tawfiq Jaber, chief of Hamas police, was among the dead in the series of strikes that took place in a period of two minutes, targeting almost all of Hamas-run security headquarters and training camps of its military wing.

Hamas and other factions has ordered fighters to respond to Israeli strikes and President Mahmoud Abbas condemned the strike as "aggression" in Gaza.

The Israel Defense Forces (IDF) spokesman confirmed to Xinhua that the army launched airstrikes at the Gaza Strip on Saturday morning, and said the offensive would continue until Gazan militants stop artillery firing at Israel.

He said some 200 rockets and mortar shells pounded Israel during the past week.

While the first series of attacks have reportedly ended, the spokesman said the Israeli army would continue the offensive until Palestinian militants in the enclave cease their "terrorist attacks" against Israel.

This is just a beginning and Israel will expand assaults in Gaza if needed, he said.

Explosions still continue in Gaza and columns of black smokes were seen across the Gaza Strip, with at least 10 pillars of smoke were seen clearly in Gaza city.

Civilian vehicles helped the ambulances in transporting the wounded and dead people to hospitals that urged the people to rush and donate blood.

The Hamas sources said more than 30 security compound were bombed.

(Xinhua News Agency December 27, 2008)