While neither Prime Minister Ehud Olmert nor Defense Minister Ehud Barak released statements following a Kassam rocket attack on Sderot on Thursday, Foreign Minister Tzipi Livni issued an uncharacteristically sharp demand for an immediate military response. The rocket hit the Sderot industrial area on Thursday afternoon, exploding near a gas station and shattering the truce for a fourth time this week. No casualties or damage to property were reported in the attack. At the beginning of a meeting with visiting Norwegian Foreign Minister Jonas Gahr Stoere in Tel Aviv, Livni told her counterpart about the attack and said there was a similar hit two days ago. "It doesn't interest me who fired it, we need to respond militarily and immediately to every infraction [of the cease-fire] like this," she said. Livni said she made her position clear to both Olmert and Barak after the rocket fire on Tuesday, and that she intended to make her position known to her counterparts around the world. Olmert's spokesman only said he held consultations regarding Israel's response. Tuesday's rocket attacks led to the closing of the Gaza crossings, and it was not immediately clear when Israel would re-open them. One government source said it seemed that Livni's response, more typical of the Likud's Silvan Shalom or Gideon Sa'ar than the foreign minister, was made with an eye on the September Kadima primary and was an attempt to capture the party's right flank. "This is not characteristic of Livni," the source said. "She is generally the one who wants to think twice, and is worried about [PA President Mahmoud] Abbas's standing." The source added that Olmert and Barak, who pushed for the cease-fire earlier this month over the objections of a number of key cabinet ministers, were not interested at this time in bringing about its complete collapse with a heavy military response. Deputy Premier Haim Ramon said the cabinet should convene once more to discuss the truce agreement. In his meeting with the Norwegian foreign minister, Ramon said he was not surprised by Palestinian violations of the cease-fire. "If Israel does not react strongly and close the crossings [to Gaza] we will be subjected to a daily trickle of rockets in the South in an effort to force us into a pattern where any Israeli action in the West Bank is countered by Kassam fire," he warned. Meanwhile, a Hamas spokesman in Gaza said the truce was "a Palestinian national interest" and called the rocket fire an "anti-national" action. The spokesman warned other militant groups that Hamas would not tolerate further violations of the cease-fire, and urged Egypt to put pressure on them to honor the agreement. Hamas also accused Fatah of seeking to ruin the Gaza cease-fire by firing rockets at Israel, and warned all the armed Palestinian factions against violating the accord that went into effect last week. The warning came after Fatah's armed wing, the Aksa Martyrs Brigades, claimed responsibility for firing two rockets at Israel. The Aksa Martyrs Brigades announced that its members would not honor the cease-fire and accused Hamas of "betraying" the Palestinians by striking the deal. "Hamas is trying to impose a unilateral cease-fire on our people in the Gaza Strip," the Fatah group said in a leaflet. "This is national treason that can't be allowed to pass." The group said it was opposed to the agreement because it did not apply to the West Bank. It called on Abbas to intervene to reach a new agreement with Israel that would also include the West Bank. Abu Qusai, a spokesman for the Aksa Martyrs Brigades, condemned Hamas for reaching what he called a bad deal with Israel. He said in the past, the PA leadership had managed to reach better cease-fire agreements that included the reopening of the Gaza border crossings and the withdrawal of IDF troops from certain areas in the Strip. "Hamas's cease-fire is very different from the one we had under the Palestinian Authority," Abu Qusai said. "Hamas has separated between the West Bank and Gaza Strip." A senior Hamas official in the Strip accused the Fatah leadership in Ramallah of "inciting" Fatah gunmen in Gaza to breach the cease-fire. He said Thursday's rocket attacks had been aimed at preventing the reopening of the border crossings. "Fatah is not happy with the cease-fire agreement because its leaders fear that it will solidify Hamas's control in the Gaza Strip," the Hamas official said. "That's why they have instructed their men in the Gaza Strip to continue launching rockets at Israel." According to the Hamas official, Fatah's main concern was that Hamas would be given a role in running the Rafah border crossing to Sinai, a move which would give Hamas legitimacy and turn it into a major player in the Palestinian arena. PA and Fatah officials denied the Hamas accusations, saying Abbas fully supported the truce. "President Abbas believes that it's important to preserve the cease-fire because it serves the interests of the Palestinian people," they said. Hamas, meanwhile, decided to establish a "crisis committee" to follow up on the truce and document Israeli "violations." Hamas Interior Minister Said Siam said the committee would consist of representatives of various Palestinian groups and that its main mission would be to ensure that that the cease-fire was preserved in accordance with the Egyptian-brokered deal. Thursday's rocket attack came after three rockets were fired at Sderot on Tuesday, sending two women into shock and severely damaging a house. "No one in Sderot believes there is a truce, neither in the municipality nor among the residents," said Shalom Halevi, a spokesman for Sderot Mayor Eli Moyal. "We wish the government would stop being stupid and begin to take military action. We are at war, and we need to stop acting like bleeding hearts," Halevi said. "The whole world is waiting for it. But here, leaders are only looking out for themselves." Moyal, Halevi added, had said during the opening ceremony of a games factory that he did not believe the cease-fire was credible. The additional rocket fire means the Gaza border crossings are likely to remain closed, following a decision by Barak on Tuesday. On Wednesday, a Hamas spokesman said their continued closure would be seen as a violation of the truce. But Israel is unlikely to go beyond that and declare the truce a failure, security analyst Maj.-Gen. (res.) Yaakov Amidror said. "There is no Fatah in Gaza. The people who fired the rocket are fragments of what was once Fatah. They operate independently, and it would not be fair to blame their actions on Abbas," Amidror said. "What these rockets show is that Hamas does not fully control Gaza, despite what some of us thought," he continued. "That is why Hamas wants this truce so badly - it wants to be Gaza's sole ruler, and it needs quiet from us in order to act internally to consolidate its rule. So Hamas will do all it can to continue the cease-fire."