Two American troops were killed and six others wounded when an Afghan soldier armed with a machine gun opened fire, the US military confirmed Sunday.
The deaths come at a sensitive time in the 18-year-old war, with President Donald Trump eager to bring troops home and end the longest conflict in US history.
The incident occurred late Saturday in Nangarhar province in eastern Afghanistan when US and Afghan commandos were conducting a “key-leader engagement” at a base in Sherzad district.
“Current reports indicate an individual in an Afghan uniform opened fire on the combined US and Afghan force with a machine gun,” US Forces-Afghanistan spokesman Sonny Leggett said in a statement on Sunday.
Provincial governor Shah Mahmood Meyakhil said in an audio message to reporters that three Afghan commandos were wounded.
He said it was not immediately clear if the incident was a deliberate act by an “infiltrator” or an accident.
"It was not a clash between the forces. We are investigating," Meyakhil said.
Leggett also stressed the cause or motive behind the attack were not immediately known.
In a tweet, the US Army's 7th Special Forces Group (Airborne) said "several" of its soldiers had been killed or injured during combat operations in Afghanistan.
No group immediately claimed responsibility for the incident.