A US military plane with five Marines on board has crashed in Southern California.

No word yet on the fate of the crew, but the US military denied reports that the plane was carrying radioactive material when it crashed near Glamis, 35km from the Mexican border.

An agency spokesman confirmed to Agence France-Presse that a plane belonging to the third detachment of naval aviation crashed.

He added that “five Marines were on board and we are awaiting confirmation of the status of all crew members,” noting that “military paramedics were at the scene.”

The spokesman denied “rumors spreading on social networks about the presence of nuclear materials on board the aircraft.”

The aircraft was identified as an MV-22B Osprey belonging to Marine Corps Air Force Base Camp Pendleton.

The Osprey is capable of “vertical takeoff and landing” and has movable wings that can be pointed upwards to allow the helicopter to maneuver or forward for level flight like a conventional aircraft.

And in March, a plane of the same model crashed in Norway, killing four Marines on board.