A shooting has been reported at a Washington underground station that serves the US Department of Defense, BBC reported.
Two Pentagon police officers were shot at the subway entrance to the military complex, a spokesman from the US Department of Defense said.
The alleged gunman was also wounded, Pentagon police spokesman Chris Layman said. All three were taken to hospital but injuries were not life-threatening.
A security lockdown was imposed on the building for a while.
The suspect had approached the subway entrance and opened fire, Mr Layman said.
Witnesses heard gunshots in the station, called Pentagon Metro, and people screaming, Reuters reported.
Officials say an investigation is under way. It is unclear why the alleged gunman opened fire at the Pentagon police officers.
All Pentagon entrances were closed off for a brief time but have since been reopened with the exception of the Pentagon Metro entrance, the Pentagon said in a statement.