A roadside bomb struck a civilian vehicle in eastern Afghanistan on Saturday, killing an Afghan policeman and three of his relatives, a government spokesman said. The incident occurred in Khogyani district of eastern Nangarhar province on Saturday, Ahmad Zia Abdulzai said. "The bomb went off as they were en route to the district headquarters. The policeman, his father, uncle and his son were unfortunately killed in the explosion," he was quoted as saying by DPA.