Gunmen firing from a motorcycle killed a former police chief as violence surged in a southern Afghanistan Taliban stronghold, police said Friday. Abdullah Khan was killed Thursday afternoon while driving his car in Argandab, a town in the southern Zabul province about 160 kilometres northeast of Kandahar, said Zabul province Police Chief Ghulam Nabi Malakhail. Two unidentified gunmen on a motorcycle fired at Khan's car and then fled the scene, said Malakhail. No motive was known for the slaying of Khan, who was replaced 18 months ago as a district police chief in Zabul, which borders Pakistan.