There was confusion in early accounts about what occurred but police said a suspect was taken into custody with wounds after shots were fired.
MSNBC-TV reported that an officer who fired at an armed suspect may have been injured by shrapnel. Police said the suspect was taken to hospital. The officer did not identify or describe the suspect and he added that there were no additional suspects.
A U.S. government official told Reuters that initial reports were that a suspect walked into the Visitors Center, pointed a gun at one of the police officers on duty and a shootout erupted.
The official said no evidence had materialized of a connection to terrorism.
Separately, CNN reported that a person tried to gain entry into the White House but was caught.
Congress is in recess, with few lawmakers in Washington but the shooting happened just a few hours after a drill for an active shooter took place at the Capitol, creating further confusion.
The Secret Service temporarily cleared tourists from an area surrounding the White House after the incident, but activities quickly went back to normal. Capitol Hill was placed in lockdown immediately after the shooting but was later lifted.
Cathryn Leff, a licensed therapist, tweeted that she was at the visitor's center when she heard gunshots while going through a security check point.
"That moment when it goes down . Everyone is screaming & running and you can't see where the #ShotsFired are from,” tweeted Leff(@Cathrynlefflmft).
Banner / Thumbnail : Reuters