Two Palestinians were killed Thursday evening in an IAF air strike on their vehicle near Gaza's Shifa hospital. Their identity was unclear. Palestinian witnesses said the vehicle was transporting soft drinks. But the army said it attacked a vehicle carrying rockets and weaponry. The latest deaths brought the number of Palestinians killed in army strikes on Thursday to 18, according to Gaza medical officials. Thursday's dead included members of rocket squads, but also five children, ranging in age from eight to 12, who their relatives said were playing soccer when they were killed in a missile strike. The army said it had targeted a rocket-launching squad. Ahmed Dardouna, a family member, said the boys were all related - two were brothers and the others were their cousins. "They were playing soccer east of the town, not far from our houses," said Dardouna, 42. He said distraught family members located the bodies at a hospital after the boys failed to come home. Later in the day, an IAF helicopter attacked a roadblock near the home of Hamas Prime Minister Ismail Haniyeh Thursday afternoon, killing one person and wounding four others, Palestinian officials said. The attack took place about 150 meters from Haniyeh's home in the Shati refugee camp in Gaza City. Haniyeh, who has been in hiding for several weeks, fearing Israeli assassination, was not believed to be in the area. The attack appeared to be aimed at sending a message to Hamas since the area is not used to launch rockets. Israel has threatened to begin targeting Hamas leaders because of the ongoing rocket fire from other parts of Gaza. Earlier, army aircraft struck two targets in the northern Gaza Strip, killing at least one person and wounding two others, Palestinian medics said. There were no details on the target, and the IDF had no immediate comment. In a series of air strikes just after nightfall, a civilian was killed, Palestinian medical officials said. The attacks were the latest in a series of air strikes meant to halt Palestinian rocket attacks on southern Israel. The air strikes killed at least seven operatives Thursday. Hamza al-Haya, the son of hardline Hamas lawmaker Khalil al-Haya, was among those killed Thursday, Hamas said. The group said he had commanded a rocket-launching squad in northern Gaza. Khalil al-Haya is one of Hamas's top figures in Gaza, and has himself escaped assassination attempts, including an air strike that killed his brother last year. Visiting the morgue at Gaza City's Shifa hospital Thursday, al-Haya said he was proud that his son had lost his life for the Hamas cause, like many of his relatives. "I thank God for this gift," he said. "This is the 10th member of my family to receive the honor of martyrdom." Several thousand people joined the funeral procession. On Wednesday night, the IAF fired a series of missiles at the Palestinian Interior Ministry in Gaza, near where Hamas Prime Minister Ismail Haniyeh maintains an office, Palestinians reported. Haniyeh, who also holds the Interior Ministry portfolio in the Strip, was not in the office at the time, but Palestinians said that 25 people - many of them passersby - were wounded in the attack. Palestinians said Wednesday's air strikes killed a 6-month-old baby, children ages 10 and 11, and heavily damaged the offices of the Palestinian Medical Relief Society, a local humanitarian group. Dr. Abdel Hadi Abu Khoussa, the center's director, said an ambulance, medicines and most of its equipment were destroyed. "The destruction is a terrible blow to our activities and will increase the suffering of the people of Gaza," he said. 29 Palestinians have been killed and dozens have been wounded since the recent IDF anti-terror operations began on Wednesday. Palestinians say 12 of the dead were civilians, including eight children. Rebecca Anna Stoil contributed to this report.