Eight U.S. marines were killed on Saturday in the bloodiest attack on American forces in Iraq in almost seven months as troops prepared for a major assault to capture the rebel towns of Ramadi and Falluja. Violence flared across Iraq ahead of the offensive, expected any day, and U.S. planes and artillery pounded Falluja. Seven people were killed by a car bomb outside the Al Arabiya television office in Baghdad, the Interior Ministry said, and seven Iraqis died in clashes with U.S. troops in an area dubbed the triangle of death southwest of the capital. The U.S. military said the marines were killed in the restive western province of Anbar, which includes Falluja and Ramadi, but gave no details. Nine marines were also wounded. Witnesses said earlier they had seen three U.S. vehicles burning on a road east of Falluja, in the same province. It was not clear if that was where the marine casualties occurred. The deaths bring to 858 the number of U.S. troops killed in combat. The total number of U.S. troop deaths, including accidents and other causes, is now almost 1,120. U.S. marine commanders said on Friday they were preparing for a major assault on Falluja and Ramadi.