A Kassam rocket slammed into an open field south of Ashkelon overnight Thursday, causing no casualties or damage. Earlier on Thursday evening, a Grad rocket struck near a synagogue in Netivot, causing minor damage, but no casualties. In retaliation, the IDF hit four smuggling tunnels along the Philadelphi Corridor. The incidents capped a day of violence that saw several Kassam rockets and mortar shells hit the western Negev, beginning shortly after Islamic Jihad vowed revenge for a series of air strikes that killed three of its operatives. On Thursday morning, two Palestinians were killed in an IAF strike in the center of the Gaza Strip. Islamic Jihad said two of its members were killed in the attack, and a third was wounded. The three men, the group said, were returning to their homes in the Mughazi refugee camp in central Gaza after a night on patrol along the Gaza-Israel border when they were targeted. The IDF said that the group was targeted after they fired an anti-tank missile at an IDF patrol along the security fence. IDF troops entered Gaza and chased after the terrorists while directing an aircraft to their location. The IAF strike came less than 12 hours after senior Islamic Jihad commander Khaled Shalan was killed after a missile struck his car in Gaza. Islamic Jihad spokesman Abu Ahmed vowed that his group would avenge the deaths. "Our rockets and our resistance will not stop," he said. "We know where and when we will take revenge for these crimes." Since the end of Operation Cast Lead in January, Palestinians have continued to fire rockets and mortar shells into Israeli territory, often provoking a military response. On Tuesday, two waves of air strikes targeted smuggling tunnels along the Gaza-Egypt border, wounding seven people.