In the heaviest military strike against the Gaza Strip since the 1967 Six Day War, the Israel Air Force bombed over 170 targets on Saturday, killing more than 230 Palestinians, as Israel launched "Operation Cast Lead," aimed at putting a stop to Hamas rocket attacks against the South. In two waves, over 100 fighter jets and attack helicopters dropped dozens of smart bombs and hundreds of tons of explosives on Hamas training camps, headquarters, weapons storehouses, underground missile silos and command-and-control centers scattered throughout the Gaza Strip. Palestinian officials said that at least 15 civilians were among the dead in Gaza. In response, 80 Kassam rockets, Grad-model Katyushas and mortar shells pounded southern Israel throughout the day. One rocket scored a direct hit on an apartment building in Netivot, killing 58-year-old Beber Vaknin and wounding several others. As ground forces amassed outside Gaza ahead of a possible ground operation, Prime Minister Ehud Olmert and Defense Minister Ehud Barak warned that Saturday's aerial bombardment was just the opening salvo of a long operation that defense officials told The Jerusalem Post would likely last several weeks. "There is a time for a cease-fire and a time to fight," Barak said. "Now is the time to fight." Defiant Hamas leaders threatened revenge. Hamas "will continue the resistance until the last drop of blood," vowed spokesman Fawzi Barhoum. Hamas chief Khaled Mashaal called on West Bank residents to rise up against Israel in a renewed intifada. Soldiers from the Paratroop and Golani Brigades were deployed along the Gaza border ahead of the possible ground offensive. Defense officials said that anyone and anything identified with Hamas was a potential target. At least two senior Hamas commanders were killed in the air strikes. One was identified as Maj.-Gen. Tawfiq Jabar, commander of the Gaza Strip police, who was killed at the Gaza Police Academy during a graduation ceremony; 70-80 Hamas operatives were reported killed in that attack. Officials said that Israel did not plan on conquering the Gaza Strip or toppling the Hamas regime, but would likely continue the air strikes together with limited ground assaults against Hamas infrastructure and Kassam launch sites. "We will not stop until Hamas halts its rocket attacks and terrorist activity," one senior defense official said. The operation was given three goals - to stop Hamas's rocket attacks against Israel; to stop the smuggling of weapons into Gaza; and to stop Hamas's terrorist activity against Israel. "Our purpose is to hit Hamas in such a way that will force it to halt any firing and other hostile activities against Israeli citizens and against the IDF," Barak said. "We will do everything it takes to defend our citizens and bring about a significantly improved situation along our border." The IDF opened the underground military command-and-control center located at the Kirya military headquarters in Tel Aviv. Chief of General Staff Lt.-Gen. Gabi Ashkenazi manned the post together with several top generals throughout the day. OC Air Force Maj.-Gen. Ido Nehushtan was inside the IAF underground command-and-control center nearby. "The goal of the operation was to shock, awe and deceive the Palestinians," a senior IDF officer said Saturday, referring to Barak's decision to open the crossings on Friday - done to deceive Hamas into believing that Israel was delaying a military response to the rocket attacks. Reports that the cabinet planned to convene on Sunday to discuss the situation in Gaza were also aimed at deceiving Hamas. The air strikes caused widespread panic and confusion in Gaza. Black clouds of smoke rose above the Strip, ruled by Hamas since June 2007. The IDF said it had avoided striking at targets next to schools and inside densely-populated apartment buildings, but urged Gazans to stay away from Hamas infrastructure. The IDF Central Command also went on high alert out of concern that Hamas terrorists would try to infiltrate Israeli cities to perpetrate suicide bombings. Military sources said there was also worry that Hamas would try to kidnap soldiers in the West Bank and that Hizbullah might attack along the northern border. Olmert cautioned Israel's enemies against trying to take advantage of the fact that Israel was busy in Gaza. In a televised speech, Mashaal warned Israel that it would not achieve by fighting what it had been unable to achieve through diplomacy. While the Damascus-based Hamas leader maintained that his organization was interested in renewing the cease-fire with Israel, he said this would only be possible if Israel and opened all crossings in and out of the Strip. Mashaal defended his group's actions and the continued rocket attacks on Israel that led to the IAF offensive, saying Israel - and not Hamas - was responsible for the renewed bloodshed.