With Kassam rockets fired from Gaza continuing to pound Negev communities for the fourth consecutive day, the army responded in kind on Friday, striking an abandoned building which had once served as the Hamas-run interior ministry. According to Palestinian witnesses and hospital officials, one woman was killed in air strike, and at least 48 people were injured. The building, which was situated in a residential district of the Gaza Strip, sustained severe damage, the witnesses said. An IDF spokeswoman confirmed the strike, and said it targeted "a Hamas headquarters", and was part of Israel's campaign against the constant firing of rockets from Gaza into Israel. Friday evening's air strike was the second of the day. Hours earlier, the IAF targeted a cell of rocket launchers, killing one civilian and wounding three Hamas operatives. In addition, IDF troops from the elite under-cover "Duvdevan" unit killed a top Palestinian terror chief in the West Bank who was affiliated with the Al-Aksa Martyrs Brigades. Ahmad Sanakra, a Tanzim commander, was killed in the Balata refugee camp in Nablus. The PA has in recent months been unable, or at least claims to have been unable, to rein in the renegade group. Sanakra had been on Israel's wanted list for several years but repeatedly eluded capture. However, on Friday he was shot and killed by troops in what the IDF calls the "pressure cooker" tactic: a house where refugees hide is surrounded and the troops call for those hiding inside to give themselves up. Sanakra refused to surrender, however, and an exchange of fire ensued. He was killed and four of his men, also Tanzim members, were taken into custody. A commander in the Judea and Samaria Division, Brig. -Gen. Noam Tivon, praised the Duvdevan soldiers for their achievements over the last few days. Kassam rockets continued to rain down on Sderot and other Negev communities throughout Friday. Eight rockets were fired towards Sderot, two of which landed in open fields. Two rockets fired Friday afternoon landed near the Shikmim ranch, owned by hospitalized prime minister Ariel Sharon. The two rockets caused no casualties or damage. Of the four rockets that reached Sderot, one landed near a WIZO center, damaging several cars in the area.