Insurgents killed three members of Iraq's security forces on Saturday, firing from speeding vehicles on army soldiers and policemen in a northern city, officials said. Gunmen killed a policeman and two soldiers as they headed to work in a pair of separate drive-by shootings in the city of Kirkuk, police Brig. Sarhat Qadir said. Further to the north, in Mosul, a car bomb damaged one vehicle in a U.S. military convoy, but there were no reports of casualties, said Sgt. John H. Franzen. Mosul is 360 kilometers (225 miles) northwest of Baghdad. A Filipino contract worker, Francisco Luz, was shot and injured Saturday in Baghdad, police and hospital officials said. It was unclear if Luz was targeted or whether he was caught in crossfire. No other details were available.