On police officer has died and another been injured after a man rammed a car into them at a barricade outside the U.S. Capitol before being shot by authorities when he got out of the vehicle.

"One of our officers has succumbed to his injuries," Yogananda Pittman, acting chief of US Capitol Police, told a news conference.

The suspect drove a vehicle into the officers, got out of the car and lunged at them with a knife in his hand,  Pittman said.

"It does not appear to be terrorism-related but obviously we'll continue to investigate," said Robert Contee, acting chief of the Metropolitan Police Department of Washington.

The crash and shooting happened at a security checkpoint near the Capitol as Congress is on recess. The incident occurred about 100 yards (91 meters) from the entrance of the building on the Senate side of the Capitol.

The security checkpoint is typically used by senators and staff on weekdays, but lawmakers are away for recess. Fencing that prevented vehicular traffic near that area was recently removed.

The U.S. Capitol complex was placed on lockdown after the shooting and staff were told they could not enter or exit buildings. Video showed National Guard troops mobilizing near the area of the crash.

Video posted online showed a dark colored sedan crashed against a vehicle barrier and a police K-9 inspecting the vehicle. Law enforcement and paramedics could be seen caring for at least one unidentified individual.

President Biden had just departed the White House for Camp David when the incident occurred.