The IDF will continue operating in the Gaza Strip until the Kassam rocket fire against Sderot stops, Defense Minister Ehud Barak said Thursday as Hamas continued to pound the western Negev with rockets for the third consecutive day. On Thursday close to 40 Kassams hit the Negev, bringing the total number of rockets fired into Israel since Tuesday to over 115. "It won't be easy, it won't happen this weekend, but we will bring an end to Kassam attacks on Sderot," Barak said during a tour of military positions outside the Gaza Strip. "The IDF will continue its operations and deepen them to strike at the perpetrators until the firing stops." During his tour, Barak also decided to shut down all of the crossings in and out of the Strip. The decision will go into effect immediately and will last for several days, during which no food or supplies will be allowed into Gaza. Defense officials said that the objective was to escalate the pressure on the terror groups and to further disconnect Israel from Gaza. Thursday evening, an IAF aircraft bombed a car traveling in the northern Gaza Strip, killing two Islamic Jihad operatives and a civilian. The IDF said that the car's occupants were members of a Kassam rocket squad. Earlier in the day, a Popular Resistance Committees operative and his wife were killed after the IAF bombed his car in the village of Beit Lahiya in northern Gaza. Prime Minister Ehud Olmert said Israel would not tolerate the continued Kassam rocket fire and would step up operations against Islamic Jihad and Hamas. "We are not looking to fight in the Gaza Strip, we do not want to harm its residents and we have no special desire to kill any citizen," Olmert told the Israel Manufacturers' Association in Tel Aviv on Thursday. "But we will not and we cannot continue to suffer the relentless Kassam rocket attacks against citizens of the State of Israel." The prime minister went on to commend the latest string of IDF operations in the Gaza Strip, which has so far killed at least 20 Palestinian operatives, and said that such military activity would continue until rocket attacks stopped. "They suffered a punch and it will not be the last one," Olmert said, adding, however, that a "button" that could be pressed and stop the rocket attacks did not exist.