A roadside bomb that missed a passing U.S. military convoy killed seven Iraqis and wounded one south of Baghdad Tuesday, police and hospital sources said, while a suicide car bomb at police headquarters in Tikrit killed six. The victims in the roadside bomb explosion were traveling in a minibus in Yussifiyah, 15 kilometers (9 miles) south of Baghdad, when the blast occurred, said the director of the town's hospital, Dawoud al-Taie. Little other information was known about the Tikrit blast. U.S. military spokesman Maj. Neal O'Brien said six were killed, while police sources said 12 were wounded. "As the Iraqi police continue to get stronger, and continue to pose a threat to the insurgents and terrorists, they will be targeted," O'Brien said.