Law enforcement officers cleared supporters of US President Donald Trump from Capitol Hill hours after they stormed the building on Wednesday, forcing a lockdown as Congress debated certifying the presidential election results.
The rioters vandalised the building, climbing the complex and entering through broken windows.
The chaos ended in an armed stand-off between law enforcement and the pro-Trump demonstrators in the House chamber, where several US politicians had taken cover.
One woman died after she was shot during the violence.
The riots forced Congress to cancel its joint session as members debated the formal certification of the election results that would formalise president-elect Joe Biden’s victory.
Capitol Hill police moved Vice President Mike Pence, who was presiding over the debate, and other US Congress members to an undisclosed secure location as rioters vandalised the Capitol.
Susan Wild, a Democratic legislator, likened the area where House members were sheltering to a super-spreader event.
Ms Wild said large numbers of her Republican colleagues, particularly new members, refused to wear surgical masks to protect others against Covid-19, despite the close confines.
Although the rioters initially outnumbered the Capitol Hill police force, the National Guard and FBI agents arrived to help remove the protesters hours later, paving the way for Congress to resume certifying Mr Biden's victory.
Before the siege, Mr Trump held a rally with thousands of supporters, urging Mr Pence and Congress to overturn the election results, which the vice president does not have the power to do.
Mr Trump once again tweeted that his deputy should block the certification even as his supporters laid siege to the Capitol.
After hours of chaos, he posted a video on Twitter telling his supporters to go home.
But he spent most of the video repeating unsubstantiated claims of voter fraud.
Mr Trump posted the video after Mr Biden delivered a speech calling on the president to tell his supporters to leave Capitol Hill.
Twitter, Facebook and YouTube and have since removed Mr Trump’s video. Twitter also locked Mr Trump’s account for 12 hours and warned that it may permanently suspend the president from the platform if he continued to violate its policies.”
The congressional certification process is typically a banal, ceremonial process.
But House Republican leaders and at least 10 Republican senators have tried to launch a doomed bid to block the certification, echoing Mr Trump’s unsubstantiated claims.
In response to the riots, the Mayor of Washington Muriel Bowser, ordered a curfew in the city from 6pm on Wednesday to 6am on Thursday.
Far-right extremist groups such as the Proud Boys have joined the throngs of pro-Trump protesters demanding that Congress overturn the election results based on debunked claims of voter fraud.
Protesters on Capitol Hill steps waved American flags, Confederate flags, Trump flags and the yellow Gadsden flag, which bears a coiled snake with the phrase, “Don’t tread on me.”
The Gadsden flag was designed as an anti-British symbol during the American Revolution and became popular in South Carolina in the lead-up to the Civil War.
In the modern US, it has become popular among conservatives and libertarians who associate it with gun rights and opposition to government restrictions.
Elaine Luria, a Democratic representative, tweeted that she had to abandon her office over reports of a pipe bomb.