A gunman shot several people at the Naval Sea Systems Command Headquarters in Washington, D.C.
According to CNN, three shots were fired at 8:20 a.m. on Sept. 16, 2013, wounding at least one person.
An official on the scene also told CNN that "several" people sustained injuries, "according to phoned-in reports from the building."
UPDATE 10 a.m. ET: The U.S. Navy (via Twitter) confirms "several injuries with reports of fatalities at #NavyYardShooting. More to follow."
At least 3,000 people work at the Navy Yard located on 1333 Isaac Hull Avenue.
NBC News reports that the shooter is thought to have used a rifle in the Monday morning shooting that happened in building 197 located in the Navy Yard.
SWAT officers, military police, U.S. Capitol police and Washington city police are all on the scene searching for the gunman.
The U.S. Navy issued a statement on Monday morning confirming the shootings. A "shelter in place" order has been issued for all personnel on the premises.
"An active shooter was reported inside the Naval Sea Systems Command Headquarters building (Bldg. 197) on the Washington Navy Yard at 8:20 a.m. (Eastern Time). There is one confirmed injury. Emergency personnel are on scene and a "shelter in place" order has been issued for Navy Yard personnel."
The Naval Sea Systems Command's headquarters in Washington, D.C. currently employs at least 3,000 people who engineer, build, buy and maintain ships, submarines and combat systems.
Follow the U.S. Navy on Twitter for the latest updates.