WASHINGTON - Two US special forces troops killed in eastern Afghanistan on Wednesday may have been struck by friendly fire in an operation targeting the emir of Islamic State militants in Afghanistan, the Pentagon said on Friday.Pentagon spokesman Captain Jeff Davis told reporters that the military was investigating if the two troops may have been killed by ground fire, either by American forces or Afghan commandos taking part in the raid, though it appeared to be accidental."We are investigating the circumstances of the combat deaths of the two Army Rangers in the beginning of what was an intense three-hour fire fight," Davis said. "It is possible these Rangers were struck by friendly fire."Earlier in the day, the Pentagon identifies the troops as Sergeant Joshua Rodgers, 22, and Sergeant Cameron Thomas, 23. A third soldier was wounded in the operation.Davis said the target of the raid was Abdul Hasib, the emir of Islamic State in Afghanistan. The US military suspected he was killed in the operation, but could not yet confirm it.