BAGHDAD, May 24 (Reuters) - A car bomb killed three U.S. soldiers in Baghdad on Tuesday, and four soldiers were killed south of the capital the previous day when a roadside bomb exploded beside their vehicle, the U.S. military said. A spokesman said the Baghdad car bomb exploded around 1:30 p.m. (0930 GMT). The victims were members of the U.S. 3rd Infantry Division. The victims of Monday's roadside bomb were soldiers assigned to the II Marine Expeditionary Force, the military said. The attack was in Haswa, south of Baghdad. Since Sunday, at least 11 U.S. troops have been killed in action in Iraq.