Three people, including the gunman, have been killed in a shooting at Marine Base Quantico in the US state of Virginia, a base spokesman said.
The incident began at 11pm local time last night with a shooting which left one person dead, said Lieutenant Agustin Solivan.
That shooting led to a stand-off between authorities and the gunman, who was barricaded in barracks at the base.
Authorities entered the barracks early today and found the attacker dead from a self-inflicted gunshot wound, along with a second victim.
Lt Solivan could not say what prompted authorities to enter the barracks.
No names were immediately released but Lt Solivan said the gunman and both victims were Marines.
Authorities believe the gunman was a staff member at the officer candidate school at the base, Lt Solivan said.
The base was put on lockdown after the shooting, but that was lifted early today.