Three Americans died after an "aircraft mishap" in eastern Afghanistan on Thursday, military officials said.
Two of the people who died were service members and the other was a civilian. All were all part of the International Security Assistance Force.
A defense official confirmed to NBC News that all of the people killed were Americans. ISAF initially reported the incident without saying the nationalities of the people killed.
No other details, including the identities of the victims, were available.
On Dec. 17, a Blackhawk helicopter crashed in southern Afghanistan, killing six U.S. soldiers. Military officials said on Thursday that the chopper was brought down by an enemy explosion.