The Karni crossing is to remain closed until further notice, Defense Minister Shaul Mofaz decided Thursday, after new information on concrete threats by terror groups to attack it was revealed in a meeting with the senior security echelon. Mofaz is scheduled to reassess the situation on Saturday night, security officials said. "The security of the citizens of Israel is first and foremost," Mofaz told the forum. The failure of the PA security forces to act against terror groups planning to launch attacks leaves Israel with no alternative but to shut it down, security officials said. At the same time, the PA continues to reject Israel's offers to use the Kerem Shalom and Sufa crossings in southern Gaza as a temporary alternative until the situation is alleviated, the officials said. "The PA's refusal to ease the situation and ensure the Palestinian public living in Gaza receive the basic food staples by agreeing to use the alternative crossings is clearly a political decision," a ministry official told The Jerusalem Post. "The defense minister made it perfectly clear that Israel intends to reopen the Karni crossing once the threat is lifted, and the other options offered to the Palestinians are temporary measures only," the official said. "On Wednesday we thought to open the crossing for 24 hours, but the imminent terror threats prevented that from happening," another official said. Currently there is no shortage of basic food staples in Gaza, however the situation has forced Palestinian farmers to sell their produce locally rather then marketing it abroad, at a significant financial loss, security officials said. The cargo crossing has been shut down a number of times due to terror threats since the beginning of the year. The last time came after a mysterious explosion in the middle of the night on February 22. At the time Israeli security officials estimated that a tunnel dug by terrorists that had been rigged with explosives blew up prematurely. When open, the crossing handles over 600 truckloads daily. Meanwhile, at the same meeting, Mofaz ordered the security establishment to step up intelligence efforts and instructed the army to beef up its presence on West Bank roads due to the recent terror attacks there. Nine Kassam rocket were fired at the western Negev on Thursday, no one was wounded and no damage reported. The army said that they were only able to determine where two of the rockets fell - one near the northern Gaza security fence and another not far from Sderot. Before dawn, soldiers arrested five unarmed Palestinians caught attempting to cross into Israel near Kerem Shalom. They were handed over to security officials for questioning. In the West Bank, security forces arrested two Palestinian youths carrying knives, one at a checkpoint near Tulkarm where a 17 year old was caught with a 30 cm. knife. He later told security officials he had planned to stab soldiers. In the afternoon, soldiers arrested a youth in Hebron caught with a knife. Security forces also arrested five Palestinian fugitives.