Violent supporters of President Donald Trump have breached the Capitol in Washington, as lawmakers met to confirm President-elect Joe Biden’s poll win.
In dramatic scenes, demonstrators swarmed the building as Congress members were escorted out by police.
Mr Biden said the action should “end now”, and Mr Trump released a video message asking supporters to go home.
The joint session of Congress certifying Mr Biden’s win has been suspended and forced into recess.
There are reports of guns drawn in the building and at least one person shot. A woman was reported to be in a critical condition after receiving a neck injury.
There has been an armed confrontation at the doors of the House of Representatives. Tear gas has also been used.
Members of Congress have been told to evacuate the building or remain where they are. One congresswoman tweeted that she was staying in her office.
Mr Trump recorded a video message on Twitter calling on supporters to leave the Capitol, but continuing to make unsubstantiated claims that Democrats had stolen the election.
“I know your pain, I know you’re hurt,” he said. “You have to go home now, we have to have peace… we don’t want anybody hurt.”
Mr Biden said the demonstration “borders on sedition and it must end now”.
“At this hour our democracy is under unprecedented assault,” he said.
Mr Trump’s spokeswoman, Kayleigh McEnany, tweeted that the National Guard was being deployed.