A U.S. military plane has crashed in eastern Afghanistan, resulting in the deaths of three Americans. There are no indications that the aircraft was brought down by enemy fire, said a defense official.

"International Security Assistance Force service members and one ISAF civilian died following an aircraft mishap in eastern Afghanistan today," said a statement released by NATO in Afghanistan.

A defense official told ABC News that the incident involved an MC-12 reconnaissance aircraft flying a nighttime mission over eastern Afghanistan.

MC-12's are Beechcraft propeller aircraft that carry multiple surveillance systems that enable the monitoring of different areas at the same time. The feeds are monitored by technicians who fly in the rear of the small aircraft.

The crash comes on the same day that an ISAF spokesperson confirmed that a Blackhawk helicopter crash in mid-December that killed six soldiers was the result of "enemy action."

The spokesperson said that the families of the six soldiers were notified Thursday that "enemy action caused the crash and loss of life."

At the time of the crash, on December 17, defense officials said there had been no indications that enemy fire had brought down the helicopter.

The investigation into the crash continues, so no other details were provided.

A defense official would not go into what kind of "enemy action" brought down the helicopter, but said the investigation had determined there was no firefight on the ground after the crash.