A man who claimed to have an explosive device in a pickup truck outside the Library of Congress on Capitol Hill in Washington on Thursday surrendered to law enforcement, ending a hours-long standoff.
"He gave up and did not resist and we were able to take him into custody without incident," Capitol Police Chief J Thomas Manger confirmed on Thursday afternoon.
The police department confirmed the suspect is 49-year-old Floyd Ray Roseberry from North Carolina.
The area remains an "active scene" with further confirmation to come of whether there is an actual explosive device in the vehicle.
The Library of Congress is near the Capitol and the Supreme Court.
Parts of Independence Avenue, Constitution Avenue and Capitol Street have been closed.
Personnel working in nearby buildings were sent emails containing evacuation orders that asked them to "remain calm" and "proceed to [their] nearest assembly area".
Mr Manger told reporters that the man had parked his vehicle on a sidewalk outside the Library of Congress and told an officer who approached him that he had a bomb while holding what appeared to be a detonator.
Police do not know the man's motive, he said, and his name was not immediately disclosed.
A video livestreamed on Facebook appeared to show a man speaking from inside a truck parked on a sidewalk outside of what looked like the Library of Congress.
"The revolution's on; it's here," the man said. "I'm trying to get [US President] Joe Biden on the phone."
Police did not say whether the video was made by the suspect.
Law enforcement officials said investigators were at the scene and working to determine whether the device was an operable explosive.
The officials were not authorised to publicly discuss the matter and spoke on condition of anonymity.
The incident comes months after a pipe bomb was left at the headquarters of the Democratic National Committee and the Republican National Committee in Washington ——a day before thousands of supporters of former president Donald Trump stormed the US Capitol in January in an attempt to overturn the presidential election results.
The US Congress is not in session this week, but Congressional staffers near the area have been told to shelter in place.
The US Department of Homeland Security issued a new national terrorism advisory bulletin last week urging caution in the weeks leading up to the 20th anniversary of the September 11, 2001, attacks in New York City and Washington.
News agencies contributed to this report