Capitol Police investigate 'active bomb threat' near Library of Congress

Several governmental buildings in Washington, D.C., were evacuated Thursday morning due to what Capitol Police call "an active bomb threat investigation" after a man drove a pickup truck onto a sidewalk.

Law enforcement negotiators are working to make contact with the person in the vehicle, law enforcement sources told ABC News.

Negotiation is still ongoing to have a "peaceful resolution" and the suspect's motives were unknown, Capitol Police Chief J. Thomas Manger said in a press conference around noon local time.

PHOTO: Police activity is pictured near the Cannon House Office Building, which is being evacuated due to a suspicious vehicle at 100 block of 1st St., SE, according to a law enforcement sources. The Library of Congress is also being evacuated.
ABC News
ABC News
Police activity is pictured near the Cannon House Office Building, which is being evacuated...Read More
The suspect told responding officers he had a bomb, and responding officers said he had what appeared to be a detonator in his hand, Manger said.

Authorities are also investigating a video posted to Facebook that purports to have been posted by the man in the vehicle.