St.-Sgt. Yehuda Basel, 21, from Moshav Yinon was killed on Thursday during the IDF incursion into the northern Gaza Strip. The circumstances of his death were being investigated, but it was becoming clearer that the fatal shot came from friendly fire and not from a sniper, as originally thought. On Thursday, the IDF took over the remains of three settlements evacuated during last year's disengagement in the face of fierce resistance as dozens of tanks and armored personnel carriers began carving out a temporary buffer zone in northern Gaza to stop Kassam rocket attacks. At least 30 Palestinians were killed during Thursday and Friday's fighting, according to the IDF and hospital officials in the Gaza Strip. Palestinian Authority Health Ministry spokesman Khaled Radi said he did not know how many civilians were among the dead. Radi said 62 people had been wounded, including seven in serious condition and 20 children. Columns of IDF tanks and APCs carrying Golani and Givati infantry rolled into northern Gaza before dawn Thursday and retook the settlements of Nisanit, Dugit and Elei Sinai, as Israel dramatically expanded its incursion into Gaza. The troops began deploying in a temporary buffer zone designed to prevent Palestinians from firing Kassam rockets into southern Israel. It was Israel's largest operation in Gaza since disengagement took place almost a year ago. Throughout Thursday, the IAF targeted Palestinian gunmen while tanks took up positions between tightly packed Palestinian homes. Apache helicopters hovered overhead, firing flares and providing machine-gun cover for ground forces engaged in skirmishes with masked Palestinian gunmen. Late Thursday night, at least four Palestinians were killed when an IAF helicopter fired missiles at a group of gunmen in northern Gaza. The IDF was checking claims that a tank shell had hit a home in Beit Lahiya and killed eight Palestinians. PA Interior Minister Said Siam of Hamas issued his government's first call to arms since IDF ground forces invaded Gaza last week, appealing to all Palestinian security forces to fulfill their "religious and moral duty to stand up to this aggression and cowardly Zionist invasion." Some of the toughest fighting took place in the village of Atatra, located near the former settlement of Dugit. IDF troops took up positions in homes there and worked to draw gunmen out of their hiding places in an effort to deal a severe blow to the terror infrastructure in the Strip. Basel, 21, from Moshav Yinon, was part of a force that had taken up a position in a Palestinian home in Atatra. He was shot in the head by a sniper as he passed an open window. Basel was treated by medics at the scene and was airlifted to Soroka Hospital in Beersheba in critical condition. He later died of his wounds. Another soldier was lightly wounded during the fighting in the northern Gaza town. OC Southern Command Maj.-Gen. Yoav Gallant said the IDF did not plan on reoccupying the Gaza Strip but was only interested in stopping the Kassam rocket attacks on the western Negev. Nevertheless, terrorists succeeded in firing eight Kassams on Thursday. No one was injured but one rocket set a field ablaze outside of Sderot. "We are working according to a system of raids and not occupation," Gallant said. "Our actions are also meant to create the right conditions for Shalit's release. We see this as a goal and will act accordingly." IDF officers predicted that the operation in Gaza would last for up to several weeks, or for as long as it took to stop Kassam attacks and retrieve Shalit, abducted from his IDF outpost near Kerem Shalom on June 25. Defense Minister Amir Peretz called the incursion into northern Gaza a "necessary step that could not have been avoided." In a meeting with Prime Minister Ehud Olmert and security officials, he said troops would continue to act "resolutely against Palestinian terrorists," and that the gradual buildup to the military operation during the past two weeks had provided legitimacy for the massive ground operation. "Return Gilad alive and well [and] stop the rocket launches, and we will return our soldiers to their bases," he said. "We have no interest in sinking in the Gaza swamp."