Three US soldiers were killed in a road accident in southern Iraq, pushing up the number of US troops killed in December to nine, the US military said Wednesday according to dpa. The deaths bring the number of US soldiers killed in Iraq since the March 2003 US-led invasion to 4,216, the Voices of Iraq (VOI) news agency was quoted by dpa as reporting. Also Wednesday, four Iraqi soldiers were wounded in an explosive attack that targeted their patrol vehicle in eastern Mosul. "Two of them were critically wounded," the source told VOI, adding that the vehicle was damaged in the attack. Also in Mosul, seven civilians, including two children, were injured in a suicide bombing, a local source said.