The attack aircraft, assigned to the 354th Fighter Squadron from the 355th Wing, "unintentionally" released an M-156 rocket while on a training mission, Davis-Monthan Air Force Base said in a statement.
The M-156, according to CBS News, is a white phosphorous projectile used to mark targets. The rocket landed in the Jackal Military Operations Area, located about 60 miles northeast of Tucson, Arizona.
The Air Force says that no injuries, damages, or fires have been reported.