Authorities at a North Dakota military base on Friday are searching for an M-240 machine gun that has been unaccounted for since Wednesday, officials said.
The 7.62mm caliber weapon was missing from the Minot Air Force Base, The Minot Daily News reported.
The Air Force Global Strike Command directed an immediate inventory search of weapons in the 5th Bomb Wing and 91st Missile Wing, the report said.
The Air Force sent 100 airmen to walk the entire six-mile route where the military explosives were likely lost, The Washington Post reported, citing a statement from the local Mountrail County sheriff.
The military has offered a $5,000 reward for information leading to the recovery of the container with the ammunition, The Minot Daily News reported.
Kenneth Halvorson, the Mountrail County sheriff, said in a statement to The Post that the missing ammunition is a belt of linked grenades for the MK 19 automatic grenade launcher.
"This ammunition is specific to that launcher and will not operate in any other launching device without catastrophic failure," Halvorson said.
The Associated Press contributed to this report.