U.S. Capitol Police Thursday said they are investigating an active bomb threat after a man parked in a vehicle claimed to have explosives.  Capitol Police Chief Tom Manger told reporters that officers responded to a call after a man drove a pickup truck onto the sidewalk in front of the Library of Congress, just east of the Capitol building. The driver of the truck told the responding officer that he had a bomb, and the officer saw he appeared to have a detonator in his hand. Manger said the Library of Congress and nearby Congressional buildings were evacuated, and that officers continued discussions with the man. Police said they could see something in the truck but could not confirm he had explosives.  Media reports, citing unnamed sources not authorized to talk to the media, say police were communicating with the suspect as he wrote notes and showed them to police from inside the truck, to which they would write back using a “white board.”  Meanwhile, sources tell NBC News the man is reported to be live streaming the standoff on Facebook. They say the police know who the man is but will only say he is from North Carolina, and that he is making anti-government statements. Capitol police would not confirm those reports. Some information in this report was provided by the Associated Press and Reuters news organizations.  
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