(Adds internal violence, two dead) By Nidal al-Mughrabi GAZA, Aug 14 (Reuters) - Israeli forces killed six Palestinians on Tuesday when they clashed with militants during a raid on the Hamas-controlled Gaza Strip, Palestinian militant and hospital sources said. Two Hamas militants and a 40-year-old bystander were killed during the raid on the southern villages of Qarara and Abassan, hospital officials said. Hamas said another of its gunmen and his mother were shot and killed as they emerged from their home in the area. At least 16 Palestinians were wounded in the fighting in which the Israeli troops were backed by military aircraft. Militant group Islamic Jihad said one of its members was killed and at least four were wounded by a missile strike during the raid. Two members of Hamas's Executive Force were killed in internal clashes between the militant group and a prominent Gaza clan, who was involved in the abduction of British journalist Alan Johnston, the group said. Witnesses said hundreds of Hamas gunmen were surrounding a house in Gaza City belonging to the Doghmosh clan and were exchanging fire with armed members held up inside. A Hamas source said the clashes erupted after Hamas forces came under fire as they attempted to retrieve a car stolen by a clan member. An Israeli army spokesman said its operation was aimed at finding a suspected militant tunnel network at the Gazan frontier and to prevent cross-border rocket fire. "During the operation, our forces encountered gunmen and fired on them, hitting at least four," the spokesman said. The army said it rounded up some 100 Palestinians for interrogation and "took several dozens of them to Israel for further interrogation" . Soldiers discovered a bomb and an explosive belt during the raid, the army said. During the clash in the mostly residential area, Hamas said its militants fired assault rifles and rocket-propelled grenades at the Israeli force. Witnesses said tanks responded with machinegun fire and Israeli snipers shot at the militants from rooftops. Israeli aircraft fired two missiles that wounded seven gunmen, they said. Hamas's armed wing, the Izz el-Deen al-Qassam Brigades, vowed in a statement to continue the fight against Israel "until either victory or martyrdom". Israel has tried to isolate Hamas in the Gaza Strip, which the group seized by force in June in fighting with Palestinian President Mahmoud Abbas's secular Fatah faction.
