A police commander was killed Saturday in a roadside bomb attack in southern Afghanistan, an official said. \"Rahmatullah, the police chief for Dand district of Kandahar province, was going to investigate a checkpoint attacked last night by the insurgents when he was killed and his bodyguard injured by a roadside bomb,\" provincial police chief Abdul Razeq was quoted as saying by DPA. He said two insurgents were killed in the clash at the checkpoint.