Gunshots were reported in the U.S. Capitol Visitors Center on Monday, U.S. Senate sources said.
Workers in the Capitol were told to "shelter in place."
A Capitol Police spokeswoman had no immediate comment but said the office would be issuing a statement soon....
UPDATE: Only remaining question is the identity and motivation of the shooter:
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.