Police say at least 12 people have died in the shootings at the Washington Navy Yard.
DC Police Chief Cathy Lanier said during a news conference yesterday that 12 people were confirmed dead.
Lanier says people were told to stay in their homes and out of the area while the authorities search for two other possible suspects. One of the shooters was killed.
The police chief says officers searched for two other people with firearms wearing military-style uniforms.
Reports are that as many as three gunmen opened fire inside one of the navy's oldest buildings, attacking office workers at the heavily guarded military facility
The attack unfolded just a short distance from the White House and the US Capitol at a former shipyard that is one of the navy's oldest shore facilities.
The building that was targeted was the military's headquarters for Naval Sea Systems Command, which buys, builds and maintains ships, submarines and combat systems. About 3,000 people work at the headquarters, many of them civilians.
Witnesses described a gunman opening fire from a fourth-floor overlook, aiming down on people in the first-floor cafeteria. Others said a gunman fired at them in a third-floor hallway.