The US Air Force has launched an investigation after a B-52 bomber flew across the US last week mistakenly loaded with nuclear-armed missiles.
It follows reports in the Army Times that five missiles were unaccounted for during the three-hour flight from North Dakota to Louisiana.
The air force said the cruise missiles were safe at all times.
Army Times said the missiles were to be decommissioned but were mistakenly mounted on the bomber's wings.
The W80-1 warhead has a yield of five to 150 kilotons, the paper said.
The flight took place on 30 August, from the Minot Air Force Base in North Dakota to the Barksdale Air Force Base, near Bossier City, in Louisiana.
This is a monumental screw-up and an example of why nuclear weapons are best left to the pros: US Navy SSBNs.