Authorities say that US forces mistakenly killed six Afghan police and a civilian after the police fired on the Americans during an operation. A US military statement says the deaths early Wednesday resulted from a "tragic case of mistaken identity on both parts." The statement says 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, says the attack collapsed the police station's roof. Afghan and US officials were traveling from Kabul to the scene of the deaths to investigate.