Israeli Airstrike Kills Commander of Hamas Military Wing (GAZA CITY, Gaza Strip) - An Israeli airstrike killed the commander of the military wing of Gaza's Hamas rulers Wednesday, Hamas officials and Israel confirmed, in a dramatic resumption of Israel's policy of assassinating Palestinian militant leaders. Ahmed Jabari was the most senior Hamas official to be killed since an Israeli invasion of Gaza four years ago. Jabari has long topped Israel's most-wanted list. Israel blamed him for in a string of attacks, including the kidnapping of Israeli soldier Gilad Schalit in 2006. Israel said the assassination marked the beginning of an offensive. It was followed by a string of airstrikes around Gaza. MORE: Palestinian Fatah Fighters Rehabilitate in Israel On its Twitter feed, the Israeli military said it could be escalated further. All options are on the table. If necessary, the (Israeli military) is ready to initiate a ground operation in Gaza," it said. Israeli Prime Minister Benjamin Netanyahu was meeting with his senior Security Cabinet after sundown Wednesday, officials said. Israeli officials said earlier that they were considering assassinating top Hamas officials following a wave of rocket fire from the Hamas-ruled Gaza Strip at southern Israel, triggering Israeli airstrikes that killed six Palestinians. The exchanges appeared to be waning on Tuesday. The killing of Jabari seemed likely to re-ignite the flare-up. Palestinians called for punishing retaliation. Witnesses said Jabari was traveling in a vehicle in Gaza City when the car exploded. Crowds of people and security personnel rushed to the scene of the strike, trying to put out the fire that had engulfed the car and left it a charred shell. Hamas police cordoned off the area around a hospital where at least one body from the strike was taken. It was draped in a white sheet, with a burned leg poking out. Hamas said another man was killed in the airstrike. Hamas police said three other airstrikes hit other targets in Gaza City, Khan Younis and Rafah. MORE: The Circumstance of Pomp: Hamas Makes a Stately Move Outside the hospital where Jabari's body was taken, Hamas official Khalil al-Haya eulogized Jabari and threatened Israel. "The battle between us and the occupation is open and it will end only with the liberation of Palestine and Jerusalem," an emotional al-Haya said. The Israeli military said the assassination was just the beginning. "After a couple of days on ongoing rocket attacks toward Israeli civilians the (Israeli military) chief of staff has authorized to open an operation against terror targets in the Gaza Strip," military spokeswoman Lt. Col. Avital Leibovitch said. Advocates say targeted killings are an effective deterrent without the complications associated with a ground operation, chiefly civilian and Israeli troop casualties. Proponents argue they also prevent future attacks by removing their masterminds. MORE: Israel Considers Resumption of Gaza Assassinations Critics say the killings invite retaliation by militants and encourage them to try to assassinate Israeli leaders. They complain that the strikes amount to extrajudicial killings. Dovish Israeli lawmaker Dov Hanin condemned the killing. Assassinating leaders is never the solution. In place of the leaders killed, others will grow, and we will only get another cycle of fire and blood," he said. Jabari, nicknamed Abu Mohammed, was born in 1960 in the eastern Gaza neighborhood of Shejaiya. In 2006, he became the acting commander of the military wing of Hamas after his predecessor, Muhammad Deif, was seriously wounded in an Israeli attack. Jabari began as a member of Palestinian President Mahmoud Abbas" Fatah party, but switched his allegiance to Hamas after serving 13 years in an Israeli prison. He survived four previous attempts by Israel to kill him. In one attempt in 2004 his eldest son, his brother and three other relatives were killed. Heller reported from Jerusalem. Additional reporting from Sarah El Deeb in Cairo.