A police officer has been killed and another has been injured after a car rammed into the US Capitol complex.
The vehicle crashed into a security fence before the driver lunged towards the officers with a knife, police said.
The officers then opened fire and the suspect, who has not been identified, was shot dead.
In a press conference on Friday, the acting chief of police in Washington DC said the attack did not appear to be related to terrorism.
“It is with a very, very heavy heart that I announce one of our officers has succumbed to his injuries,” Acting Capitol Police Chief Yogananda Pittman said at the conference.
The exact circumstances of the officer’s death are not yet clear.
“Whether the attack was at law enforcement, or whoever, we have a responsibility to get to the bottom of it and we’ll do that,” Robert Contee, the acting chief of the city’s Metropolitan Police Department, said.
There is an increased security presence around the Capitol building, where the US Congress sits, and a number of police cars surrounding the area.
The entry point on Constitution Avenue where the vehicle struck the barricade is directly where Senators and their staff come to the Capitol each day, according to observers.
But Congress is currently in recess, meaning the majority of politicians are not at the Capitol complex today.
President Joe Biden left Washington earlier in the day for Camp David, the presidential retreat in Maryland.
However some reporters, maintenance workers and Capitol Hill employees are likely still on the Capitol grounds.
🚨🚨A helicopter just landed on the east front of the Capitol. I’ve never seen anything like this before. ever. pic.twitter.com/LxV0mywRSe
— Jake Sherman (@JakeSherman) April 2, 2021
Shortly after 13:00 local time (18:00 GMT) the Capitol Police alert system sent an email to lawmakers and their staff ordering them to stay away from exterior windows and doors. Anyone outside was instructed to seek cover.
Footage of the scene showed a helicopter flying overhead and what appeared to be two people on stretchers being moved into ambulances.
Onlookers were told to clear the area.
The FBI’s Washington Field Office is responding to the situation and is providing support to the Capitol Police. The US Attorney General is also aware of the incident and is being updated, according to CBS News.
The incident comes nearly three months after the deadly 6 January riot at the Capitol.