Washington D.C.'s Navy Yard facility is under lockdown Thursday morning, according to a Tweet from the U.S. Navy. This is the site of a 2013 shooting where 12 people were killed.

DC's Metropolitan Police Department tells CNN they are responding to the facility but there is no further information regarding the exact nature of the incident.

Police and ambulance vehicles surrounded the Washington Navy Yard on Thursday morning. Bystanders tweeted photos of the scene, though official details on the incident were scarce as of Thursday morning.

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