The US Capitol building is in lockdown after a vehicle reportedly slammed into the security barriers surrounding the complex, police say.
The suspect and the two officers were taken to hospital, police said.
CNN and the Associated Press are now reporting that the suspect has died, citing multiple sources.
CNN also reported that at least one of the two injured officers was stabbed, citing a law enforcement official.
The Capitol and surrounding streets in Washington DC are in lockdown after police warned of an “external security threat”.
Footage of the scene has shown a helicopter flying overhead and what appeared to be two people on stretchers being moved into ambulances.
Congress is currently in recess, meaning the majority of lawmakers are not at the Capitol today.
President Joe Biden left Washington earlier in the day for Camp David, the presidential retreat in Maryland. Some reporters, maintenance workers, and Capitol Hill employees are likely still on the Capitol grounds.
Shortly after 1 pm, local time 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.
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.
The FBI’s Washington Field Office is responding to the situation and is now 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.
Authorities have begun only in the past two weeks to remove the outer ring of high, razor-wire-topped fencing erected around the sprawling Capitol complex after the riots in early January.