Mass Shooting At DC Navy Yard BaseUPDATE: Twelve Fatalities Now Confirmed

The Washington Post has the early report:

A D.C. police officer is among the people shot at the Washington Navy Yard on Monday morning. A police spokesman confirmed at 9:20 a.m. that the officer was shot near the room where a lone gunman has barricaded himself after allegedly shooting at least three people on the Navy Yard grounds in Southeast Washington. The U.S. Navy said that three shots were fired around 8:20 a.m. at the Naval Sea Systems Command Headquarters building, where about 3,000 people work. Police said that at least three, possibly four, people were shot. All are in critical condition, authorities said.

A "shelter in place" order is in effect at the base. President Obama has reportedly been informed. Developing...

UPDATE: CNN reports twelve shooting victims.

UPDATE II: Russia's foreign affairs chief tweets: "A new shootout at Navy headquarters in Washington - a lone gunman and 7 corpses. Nobody’s even surprised anymore. A clear confirmation of American exceptionalism."

UPDATE III: The death toll has been raised to six.

The gunman, identified as a former Navy official in his 50s, was confirmed dead by a law enforcement official but police were looking into the possibility of two additional shooters. The D.C. police chief says a white male was last seen with a hand gun around 8:35 a.m. A black male, identified as a suspect in his 50s, was also seen with a long gun. Officials said both men were wearing military-style uniforms. D.C. Metro police confirmed that two officers were among the eight victims shot. One of them is a D.C. male police officer, and the other is from the naval base. Three of the victims were transported to MedStar Washington Center in critical condition. The Metro police officer was undergoing emergency surgery after suffering multiple gunshot wounds to his legs. A second female victim transported to MedStar was shot in the shoulder and a third suffered a gunshot wounds to her head and hand.