A police officer was shot and wounded on Monday in the US Capitol complex and the gunman captured, a source citing information from the Sergeant-at-Arms office in Congress said.
Gunshots were heard in the US Capitol Visitors Center and workers were told to shelter. The source said the officer's wounds were not serious.
Congress was in recess Monday for the Easter holiday, but it is a busy week for tourists in Washington.
"Shelter in place remains in effect as Capitol Police continue to investigate. Please stay in your assigned location," the Senate's Sergeant-at-Arms, the body's chief law enforcement officer, said on Twitter.
Police cordoned off access to the Capitol building. An ambulance was at the scene.
"There has been an isolated incident at the US Capitol. There is no active threat to the public," Washington police said on Twitter.
The White House, where thousands were attending the annual Easter Egg Roll, was briefly on lockdown as well, but the order was quickly lifted.
