(Adds new clash, updates death toll) GAZA, Nov 26 (Reuters) - The Israeli army killed two Palestinian militants and wounded four in the northern Gaza Strip on Monday, local medical workers said. An Israeli army spokeswoman said troops shot at several gunmen who had tried to plant an explosive device near the border fence with Israel. Palestinian medical workers said one militant was killed in the clash. Earlier, an Israeli missile strike killed one militant and wounded four, medics said. The army said it had targeted a group of militants who had launched two mortar shells at southern Israel. Both militants killed belonged to Hamas, the Islamist group said. Israel has stepped up air strikes and military incursions since Hamas seized control of the Gaza Strip in June. Militants often lay ambushes for Israeli troops in frontier areas and launch rockets and mortars from Gaza into southern Israel. (Reporting by Nidal al-Mughrabi; Writing by Avida Landau; editing by Tim Pearce)
