GAZA CITY (AFP) - Three Palestinians were killed on Friday in an Israeli airstrike north of Gaza City, medical sources and witnesses said. Another three were reported to have been seriously wounded. All six had been in a vehicle that was targeted by two Israeli helicopters, the sources said. The same sources said at least four of the victims belonged to the Islamic Jihad group. Those killed were named as Kamel al-Banna, Mohammed Marshoud and Kamal al-Dahtur, the son of an Islamic Jihad commander killed in an Israeli raid two years ago. An Israeli military spokesman confirmed to AFP that Israeli aircraft attacked three armed men who were preparing to fire rockets at Israel. Addressing the UN General Assembly, Palestinian President Mahmoud Abbas said Israel must stop all settlement activity in occupied territories in order to salvage the Middle East peace process. Abbas told the Assembly the international community must pressure Israel to halt its settlement building which will undermine the goal of establishing a geographically contiguous Palestinian state.