A U.S. Capitol Police officer has died from injuries suffered in Friday’s vehicle attack at the Capitol complex, police said.

The suspect also has died, police said at a briefing.

A motorist rammed a vehicle into U.S. Capitol police on Friday and brandished a knife, killing one officer and injuring another and forcing the Capitol complex to lock down in an attack that police said did not immediately appear to be terrorism-related.

Police responded by firing on the suspect, who died.

Yogananda Pittman, acting chief of the United States Capitol Police, told a news conference that he drove into the officers then hit a barricade and got out of the car, lunging at them with a knife in his hand.

One officer was killed and the other was injured, she 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.

Police said the suspect was unknown to them, they had yet to determine what had motivated him, and they did not identify him.

“Clearly this was someone who was actively trying to just get at whoever or whatever - we just don’t know right now, so we have a responsibility to investigate that to get to the bottom of this. 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,” Contee said.

Reporting by Dan Burns; Editing by Howard Goller / REUTERS