KABUL: An Afghan air force strike killed five soldiers and a police officer in western Afghanistan, an official said Saturday, the latest in a series of so-called “friendly fire” incidents. Afghan helicopters “mistakenly” bombed their own forces after calling in air support as they battled the Taliban in the Kensk area of Farah province late Friday, Dawlat Waziri, a defense ministry spokesman, said. “Because of the wrong coordinates, helicopters bombed an Afghan forces’ checkpoint that unfortunately left five soldiers and one police officers dead,” he said. “An investigation into the incident has been launched,” he added. Last month a US air raid killed eight Afghan policemen in the southern province of Uruzgan, in the first such incident since American forces were given greater powers to strike at insurgents. The US military in Afghanistan, however, said its forces were not involved in the air strike in Farah.