Shots have been fired in the US Capitol building

A U.S. Capitol Police officer was shot Monday at the Capitol Visitor Center complex, and the shooter was taken into custody, Capitol officials and police said.

The event unfolded with Congress on recess and lawmakers back in their districts.

It occurred in the Visitors Center of the sprawling Capitol Complex. Staffers, reporters and others were told to "shelter in place" and not allowed to leave their offices. The White House and the Capitol complex were put on lockdown.

The police officer who was shot was not believed to be seriously injured.

Capitol Police did not immediately return calls and no further information was available.

-Associated Press