Last Updated Mar 28, 2016 3:26 PM EDT
Emergency crews are responding to the Capitol after a shooting on the east side.
One U.S. Capitol Police officer has been shot, but not seriously, and a shooter is down, a U.S. Capitol Police source told WUSA. The Associated Press reports that the shooter is in custody. No other injuries have been reported at this time.
The U.S. Capitol and the White House are on lockdown. U.S. Capitol Police said they were locking down the entire Capitol complex in Washington due to a potential security threat. The lockdown at the White House, however, was precautionary. There is no specific threat or imminent danger to the White House, according to a law enforcement official.
An advisory was sent out to staffers warning that no one will be allowed to enter or exit any buildings. People are able to move about within buildings and underground between buildings, and if people are outside, they should seek cover.
A police officer told CBS News' Walt Cronkite that this is not part of a drill. The Senate and House are out on recess this week.
CBS News' Mark Knoller and Arden Farhi contributed to this report. © 2016 CBS Interactive Inc. All Rights Reserved.