US forces mistakenly killed six Afghan police and a civilian after the police fired on the Americans during an operation, the US army said on Wednesday. In a statement, the US military said that the deaths resulted from a "tragic case of mistaken identity on both parts." The statement said that the police fired on the US forces after the troops battled and killed an armed militant close to a police station in the city of Qalat, the capital of Zabul province. Thirteen Afghans were wounded in the firefight. Gilani Khan, the deputy provincial police chief, said that the attack collapsed the police station's roof.