Authorities said that there was no longer an ongoing threat and that the attack did not appear to be related to terrorism.
A policeman has died after a driver rammed a car into two officers at a barricade outside the US Capitol and then emerged wielding a knife, officials say.
Both officers were hospitalised and one of them died from his injuries, Capitol Police Acting Chief Yogananda Pittman told reporters.
The suspect died in hospital after he was shot by police when he attempted to lunge at them with a knife outside the building in Washington DC on Friday.
White House secretary Jen Psaki said President Joe Biden was “aware” of the attack. Mr Biden had left for Camp David when the incident happened.
Capitol Police Acting Chief Yogananda Pittman told reporters how events unfolded.
“The suspect entered what we refer to as the north barricade of the Capitol,” Police Acting Chief Pittman said.
“The suspect rammed his car into two of our officers and then hit the north barricade barrier.
“At such time the suspect exited the vehicle with a knife in hand. Our officers then engaged that suspect. He did not respond to verbal commands.”
Officer Pittman added: “The suspect did start lunging toward US Capitol Police officers, at which time US Capitol Police officers fired upon the suspect. At this time the suspect has been pronounced deceased.”