If the Kassam rocket fire on the western Negev continues unabated, the government will have to decide whether to further ratchet up its reactions by targeting top Hamas political leaders, government officials told The Jerusalem Post on Thursday. According to the officials, Israel has in recent weeks gradually stepped up its response to the Kassams, first targeting only those involved in firing rockets, then targeting well-known terrorist commanders and officials, and then going after symbols of Hamas power in Gaza, such as the strike on a Hamas police installation in Khan Yunis on Thursday that killed seven people. The next logical step, according to the officials, will have to be a decision whether to target the top political leadership, as Ariel Sharon did in March 2004 when, within the span of a month, Israel killed Hamas founder Sheikh Ahmed Yassin and top leader Abdel Aziz Rantisi. The official's comments came after IDF troops uncovered underground Kassam launch silos inside the Gaza Strip during an early-morning foray there on Thursday - underground silos similar to those from which Hizbullah fired rockets at Israel during the Second Lebanon War. During Thursday's operation, the troops killed seven Palestinian gunmen affiliated with Hamas and Islamic Jihad. Pictures released by the IDF Spokesman's Office showed two underground Kassam rocket silos, a meter in diameter and two meters deep. The launchers, the IDF said, were big enough to hold a Kassam or Grad-model Katyusha rocket that could be launched by remote control. The IDF estimates there are additional underground rocket silos throughout the Gaza Strip. Defense officials said the silos, discovered by the Golani Brigade's elite Egoz Unit, proved the need for continued ground operations inside the Gaza Strip. Despite the escalation, senior government sources said that for the time being Israel's policies will be similar to what has been seen in recent days: a combination of military, economic and diplomatic pressure on the Hamas regime. The sources said that at the top level of government there is an understanding that "there is no magic fix," and that any "quick fixes" could play into Hamas's hands. The officials said while the army has drawn up numerous contingency plans, including plans to take over the Philadelphi Corridor, these currently fall within the realm of military plans, not government policy. "We have to have patience and be sensible," one government source said. "That doesn't mean there can't be innovations in our strategy, but there are no magic fixes." Defense Minister Ehud Barak said following an exercise at the Ze'elim Training Base in the south on Thursday that "if the Kassam rocket fire from Gaza continues, then we will escalate our operations." "The IDF operations will bring results," Barak continued. "This will not end today, and not tomorrow, but the continued military action on the one hand, with the sanctions on the Gaza Strip on the other, as well as the protective measures being taken in some of the [Gaza belt] communities, will in the end bring a stop to the Kassam rocket fire." Meanwhile on Thursday, some 20 Kassam rockets pounded the western Negev. One rocket struck a direct hit on a garage adjacent to a home in Sderot, setting it ablaze and sending three people into shock. Two Kassams landed near a college in the Eshkol region. No one was wounded and no damage was reported. The other rockets all hit open areas. Terrorists also fired some 10 mortar shells from the Strip. No one was wounded and no damages were reported. The IDF operation in Gaza, aimed against Kassam launch squads, started late Wednesday night when troops from Egoz, accompanied by tanks, armored bulldozers and IAF helicopters penetrated three kilometers deep into Gaza near the Jabalya refugee camp in the north. Palestinian sources claimed that the IDF killed a teacher during the operations. Hamas security forces said that the teacher died and two other staffers were hurt when an Israeli missile struck an agricultural school in Beit Hanun. The group released no further details and school officials weren't immediately available for comment. However, the IDF said that it had fired in the area at a group of rocket launchers. "We definitely did not fire at a school," the army said, adding that it was looking into the report. Also on Thursday, the Defense Ministry instructed the Israel Electric Company to begin reducing the flow of electricity in one of the power lines to the Gaza Strip by 5 percent during the evening, Army Radio reported. The initial power cut, part of the government's punitive measures against Hamas, was expected to be followed by further 5 percent reductions in two additional lines in the next two weeks. Gaza generates about a quarter of its own electricity at a plant run on fuel imported from Israel. The rest comes from over 10 electricity lines running directly from Israel and one from Egypt. Deputy Defense Minister Matan Vilna'i said the move was another step in the process to decrease Gaza's dependency on Israel. "We alerted Hamas and Egypt of the current step through diplomatic channels. They received very clear notification. "Israel's topmost interest is to stop its connection to the Strip. We won't supply electricity to Kassam production facilities. Eventually they need to start taking care of themselves - and they will take care of themselves." The power cutback was made possible last week, when the High Court of Justice turned down appeals by several human rights groups against the planned sanctions. The US-based Human Rights Watch (HRW) on Thursday condemned the cuts in Israel's power supply to Gaza as collective punishment of the civilian population and a violation of the laws of war. "Israel views restricting fuel and electricity to Gaza as a way to pressure Palestinian armed groups to stop their rocket and suicide attacks," said Joe Stork, Middle East director of HRW. "But the cuts are seriously affecting civilians who have nothing to do with these armed groups and that violates a fundamental principle of the laws of war." HRW added that indiscriminate Palestinian rocket and suicide bomb attacks against Israeli civilians constituted war crimes, but Israel's attempts to suppress those attacks must not also violate international humanitarian law. Dan Izenberg and AP contributed to this report.