A car bomb exploded Saturday in central Iraq, killing five people, including four police officers on patrol, while gunmen killed an education official in Baghdad. The car bomb in Khan Bani Saad, near the troubled city of Baqouba in central Iraq, also injured two police officers and three civilians. In Baghdad, gunmen opened fire from a car, killing Hassib Zamil outside of the Education Ministry offices in the Sadr City neighborhood, education official Ibrahim Abid Wali said. Late Friday, insurgents fired a rocket propelled grenade and shot at an armored vehicle used to transport U.S. troops on a road leading to the dangerous airport highway, the U.S. military said. It was unclear if there were casualties.