There was no immediate word on casualties, but the official said the plane's wreckage was scattered over a large area.
The C-130, en route from Baghdad to the city of Balad, was confirmed down about 40km northwest of Baghdad, according to the official.
Helicopters were at the scene and observed the wreckage, the military official said.
Britain's Ministry of Defence confirmed the crash but said
it had no details on the cause or location.