US Capitol: Police regain control after Donald Trump supporters storm building, with four dead and bombs found

Police have regained control of the US Capitol after supporters of outgoing president Donald Trump stormed the building, with one woman shot dead and explosive devices found.

Three other people died of "medical emergencies" during the protests, Washington DC police confirmed, with officers making 52 arrests.

In dramatic scenes that drew international condemnation, supporters of Mr Trump brought violence to the seat of America's democracy on Wednesday - prompting the US Capitol to be put into lockdown.

Fallout as FBI hunt those who stormed Capitol - follow live updates

The White House revealed the US National Guard had been called in by Mr Trump following clashes between rioters and police, while a curfew was ordered across the city.

As darkness fell, the FBI were also on the ground clearing remaining protesters.

Groups of Trump supporters breached metal barricades and stormed their way into the Capitol building as they disrupted the confirmation of US president-elect Joe Biden's victory in November's election - a fortnight before his inauguration ceremony.

Local emergency services earlier said one person was in a critical condition after being shot and at least five people - including a law enforcement officer - had been taken to hospital.

NBC, quoting law enforcement officials, said several improvised explosive devices were found on Capitol grounds - as did the Associated Press.

And Mr Trump's Republican Party - parts of which the president has criticised for failing to fully support his unproven claims of election fraud - revealed a suspicious device was found at their headquarters before being detonated by a bomb squad.

Both chambers of Congress were abruptly suspended as they debated Mr Biden's election win - which Mr Trump continues to vociferously dispute despite unsuccessful legal challenges - when the violence flared.

US Vice President Mike Pence was ushered out of the Senate chamber to a secure location as protesters entered the building.

In a televised address, Mr Biden said America's democracy was "under unprecedented assault" as he condemned the "small number of extremists dedicated to lawlessness" who had brought "chaos" to the Capitol.

"This is not dissent, it's disorder. It's chaos. It borders on sedition and it must end, now," Mr Biden added.

"I call on this mob to pull back and allow the work of democracy to go forward."

The president-elect urged Mr Trump to go on national television to "defend the constitution" and "demand an end to this siege".

Mr Trump chose to post a minute-long video posted to his Twitter account.

He did not explicitly condemn the scenes of violence, but urged those who had gathered at the US Capitol to disperse.

"I know your pain, I know your hurt - we had an election that was stolen from us," he said.

"It was a landslide election and everyone knows it, especially the other side."

Calling on his supporters to leave the Capitol, the US president added: "You have to go home now, we have to have peace, we have to have law and order, we have to respect our great people in law and order.

"We don't want anybody hurt, it's a very tough period of time - there's never been a period of time like this where such a thing happened, where they could take it away from all of us.

"From me, from you, from our country."

Twitter swiftly added a warning message to Mr Trump's video, which read: "This claim of election fraud is disputed, and this Tweet can't be replied to, retweeted, or like due to a risk of violence."

Facebook and YouTube went further and removed Mr Trump's video completely.

"This is an emergency situation and we are taking appropriate emergency measures, including removing President Trump's video," said Facebook's vice president for integrity, Guy Rosen.

"We removed it because on balance we believe it contributes to rather than diminishes the risk of ongoing violence."

Mr Trump later added in another tweet: "These are the things and events that happen when a sacred landslide election victory is so unceremoniously & viciously stripped away from great patriots who have been badly & unfairly treated for so long."

The president lost November's election to Mr Biden by 306 Electoral College votes to 232. He was also beaten by more than seven million votes in the popular vote.

Democrat senator Jeff Merkley said that officials had "rescued" Electoral College ballots from the Senate floor during Wednesday's session of Congress.

"If our capable floor staff hadn't grabbed them, they would have been burned by the mob," he posted on Twitter.

The ceremony to certify the election result disrupted on Wednesday night resumed when protesters were cleared, with Mr Trump forced to issue a new statement agreeing to an "orderly transition" of powers.

Mr Trump and the Republicans have now also lost control of the US Senate, after the Democrats on Wednesday won two runoff races in the state of Georgia that had been too close to call in the November elections.

That means Mr Biden will hold the all-important three political levers of the White House, House of Representatives and Senate.

Mr Pence had earlier called for the "violence and destruction" to stop and warned "this attack on our Capitol will not be tolerated and those involved will be prosecuted to the fullest extent of the law".

The chaotic scenes came after Mr Pence had defied the president by saying he would not intervene in the confirmation of Mr Biden's victory by Congress.

Mr Trump turned on his vice president, claiming Mr Pence "didn't have the courage to do what should have been done".

As the violence unfolded, Ivanka Trump - the president's daughter and adviser - deleted a tweet referring to "American patriots" before she posted another tweet condemning "unacceptable" violence.

A 12-hour curfew, beginning from 6pm local time, was ordered in Washington DC by the city's mayor.

Former Republican president George W Bush said he and his wife, Laura, were "watching the scenes of mayhem... in disbelief and dismay".

"It is a sickening and heartbreaking sight," he said.

"This is how election results are disputed in a banana republic - not our democratic republic."

Prime Minister Boris Johnson condemned the "disgraceful scenes", adding: "The United States stands for democracy around the world and it is now vital that there should be a peaceful and orderly transfer of power."

Labour leader Sir Keir Starmer said: "Horrendous scenes from the US. These are not 'protesters' - this a direct attack on democracy and legislators carrying out the will of the American people."

NATO general secretary Jens Stoltenberg said: "The outcome of this democratic election must be respected."

Ursula von der Leyen, the president of the European Commission, posted on Twitter: "I believe in the strength of US institutions and democracy. Peaceful transition of power is at the core."

She added that Mr Biden "won the election" and said she would "look forward to working with him as the next President of the USA".

Mr Biden is due to be inaugurated as the next US president on 20 January, with a US Capitol ceremony set to take place where rioters gathered on Wednesday.