The objection to certifying Biden's win in Pennsylvania has just been rejected by the Senate 92-7.

Senate leader Mitch McConnell moved to end debate on the matter after Senator Hawley yielded his time, sparing everyone in the upper chamber a two-hour discussion.

McConnell says he does not expect any more challenges to the election results tonight.

But over in the House, lawmakers are continuing to debate the objection.

An objection to the election results in Pennsylvania does have a senator’s signature.

Josh Hawley, of Missouri, has put his name to the House Republicans' challenge.

The House and Senate must now separate for up to two hours of debate, though both chambers are ultimately expected to dismiss the objection.

The challenge has been levied on the grounds that the results in Pennsylvania, where Biden won, "were not under all of the known circumstances regularly given".

Applause has just rippled across the Senate floor as three Republican objections to the presidential election results were dismissed by Pence because no senator had signed on, a procedural requirement.

One challenge was presented by Jody Hice, a congressman who was just elected to his home state of Georgia in November.

Another Georgia representative, Marjorie Taylor Greene, objected in vain to Michigan's electoral votes. The newly elected congresswoman has in the past expressed support for the QAnon conspiracy theory.

The third challenge to be dismissed was brought forward by Alabama congressman Mo Brooks, who was objecting to the results in Nevada.

Image source, Getty Images

Police officers in riot gear continue to guard the streets around the Capitol. Washington's mayor has issued an overnight curfew.

The DC police chief says as of 21:30 local time they had made 52 arrests, 4 for carrying pistols without licences, 1 for carrying prohibited weapons, 47 for curfew violations and unlawful entry.

Two pipe bombs have been recovered, one from the Democratic National Committee offices, not far from the Capitol, and one from the nearby Republican National Committee headquarters.

Image source, Getty Images

Image source, Getty Images

DC Mayor Bowser and police chief Robert Contee just held a presser about the Capitol Hill protest.

They said the woman who was shot was part of a group of multiple individuals that forced entry into the House room that was still in session.

They were confronted by plainclothes officers, and an officer pulled out a weapon and fired it.

The woman was taken to hospital and proclaimed dead. Her ID is being withheld by authorities until next of kin are notified.

They said of the three other deaths today at the Capitol grounds, one was an adult female and two were adult males. All three involved unspecified, separate medical emergencies.

At least 14 members of the Metro police department were injured. Two were admitted to hospital, one with serious injuries after being dragged into the crowd, and the other was hit by a projectile in the face.

Washington DC police say four people have died during the storming of the Capitol building.

In addition to the woman shot by police, three others died as a result of "medical emergencies".

So far, more than 52 people have been arrested - 47 of them for curfew violations.

US media are reporting the woman shot and killed during the storming of the Capitol was San Diego resident Ashli Babbitt. A US Air Force veteran, she is thought to have been shot after entering the building alongside other protesters.

US broadcaster Fox5 spoke to the woman's mother-in-law, external who said Babbitt had been a Trump supporter.

She is thought to have been shot at around 15:00 Washington time, and was rushed to hospital but later pronounced dead.

The mayor of the US capital city has extended a public emergency for 15 days until after inauguration day.

"Many persons came to the District armed and for the purpose of engaging in violence and destruction and have engaged in violence and destruction. They have fired chemical irritants, bricks, bottles and guns," Mayor Muriel Bowser said.

"Their motivation is ongoing."

The declaration will allow the city to draw upon additional resources to protect residents, like enforcing curfews, expanding emergency services or distributing necessities.

The order lasts until 15:00 on 21 January, the day after Biden will be sworn in.

The city is already under curfew declared by the mayor from 18:00 on Wednesday to 06:00 (23:00 to 11:00 GMT), though dozens of people have been arrested for violating the order.

Florida Senator Marco Rubio says he grew up among people who came to the US because their country was chaotic, just like the scene that played out today.

The Republican adds that rivals like Russia and China are laughing at America today, and will use the incident to suggest America is in decline.

"There's nothing Vladimir Putin could have come up with better than what happened here. It makes us look like we're in total chaos and collapse."

"I think politics has made us crazy!” he adds. "Everybody in this country has lost their minds!"

At the moment, we're watching as lawmakers continue the process of certifying the Electoral College vote from the states. Biden won with 306 to Trump's 232.

The number of votes is read out state by state. If any objections are raised by both a member of the Senate and the House, then the lawmakers separate into their respective chambers and debate the matter for two hours before deciding whether or not to uphold it.

We just saw the Senate reject the objection to Arizona's vote and we expect the House to do the same in the next hour or so.

Remember, for a state's electoral votes to be tossed out, majorities in both the House and Senate must vote to do so. With more Republicans changing attitudes in the wake of today's attack, plus the House in control of the Democrats, this is all but impossible.

Want to know more about the process? Check out our explainer here: Can rebel Republicans overturn the election?

"The best way we can show respect for the voters who were upset is by telling the truth," Mitt Romney, the Republican party’s 2012 presidential nominee, said on the Senate floor.

"The truth is that President-elect Biden won the election. President Trump lost. I’ve had that experience myself," Romney said. "It’s no fun!"

Just ahead of Romney's speech, a picture of his intense stare during fellow Republican Josh Hawley's remarks went viral on Twitter.

Hawley is among the six Senators who voted in favour of the Arizona vote objection, and he has continued to question the integrity of the presidential election.

Trump loyalist Lindsey Graham has reaffirmed Biden's win.

"Count me out, enough is enough," the South Carolina senator said.

"Joe Biden and Kamala Harris are lawfully elected and will become the president and vice-president of the United States on January the 20th," he added, after an emphatic speech decrying the violence.

The objection to Arizona's results has failed, with just six Republicans (including Ted Cruz and Josh Hawley) voting in favour of it, and 93 against.

"The objection is not sustained," says Vice-President Pence.

Now, the Senate must wait for the House to knock down the objection in a vote, too.

Republican Senate leader McConnell says they expect the House's vote to finish between 22:30 and midnight.

Then, the lawmakers will all reconvene and continue to count the states' votes.

A lot has happened today.

Here's a look back at how it all unfolded.

The mob entered the Capitol at the East Entrance, though protesters had gathered on both sides.

Trump had earlier given his speech before the White House.

Watch how it played out below.

Illinois Senator Tammy Duckworth delivered an emotional speech tonight.

An ex-army pilot who had both her legs amputated after crashing in Iraq in 2004, Duckworth urged her colleagues to ask themselves if it was worth damaging this democracy to protect Trump.

"I have no tea to throw in Boston harbour tonight," she said.

"And I regret that I have no rucksack to pack for my country, no Blackhawk to pilot ... nor am I asking for any grand gesture from my Republican colleagues."

Watch her speech below.

There are murmurs within Trump's cabinet about potentially invoking the 25th amendment, the BBC's partner CBS News reports.

So what is it?

It's an amendment to the Constitution that says if the president is unable to perform his duties, the responsibility can be re-designated.

In this case, it would require a majority of cabinet leaders plus Vice-President Mike Pence to write to Congress' leaders and say Pence is becoming acting-president as Trump is unfit.

The 25th amendment has never been invoked since it was ratified in 1967.

Nothing has been formally presented to Pence at the moment.

Some have already called on Pence to trigger the 25th, accusing Trump of inciting of violence, including the National Association of Manufactures chief, the head of the NAACP and Vermont's Republican governor.

"It was ugly today," said Republican Ben Sasse, Nebraska Senator, on the Senate floor.

"I don't think we want to tell our kids that America's best days are behind us because it's not true - that's not who we are."

He adds that the nation can't accomplish great things, like the moon landing, "if you hit your neighbours".

Republican Kelly Loeffler, who just lost her Georgia Senate race, also condemned the violence - and flipped her decision on ratifying Biden's win.

"I cannot now, in good conscience, object to the certification of these electors," Loeffler said.

White House Deputy Press Secretary Sarah Matthews has resigned from her post over the Capitol violence.

"I was honoured to serve in the Trump administration and proud of the policies we enacted," she said in a statement.

"As someone who worked in the halls of Congress, I was deeply disturbed by what I saw today."

Matthews said her resignation is effective immediately, adding: "Our nation needs a peaceful transfer of power."

Earlier, First Lady Melania Trump's chief of staff and former Trump press secretary Stephanie Grisham resigned amid the chaos. It was unclear whether the Capitol attack had anything to do with her departure.

"It has been an honour to serve the country in the White House," she tweeted. "I am very proud to have been a part of Mrs Trump’s mission to help children everywhere, and proud of the many accomplishments of this administration."

Social media giant Facebook has also opted to bar President Trump from posting for the next 24 hours.

The company cited policy violations on the president's page.

Image source, Getty Images

Today's attack was the first time the US Capitol was broken into since the War of 1812, according to US Capitol Historical Society experts.

British troops, led by Vice Admiral Sir Alexander Cockburn and Major General Robert Ross - set fire to the still-under-construction Capitol after invading DC in August 1814 (though the building survived thanks to a downpour).

In retaliation for the Americans' burning of Upper Canada's capital at York a year earlier, the British troops also set fire to other parts of the city, including the White House.

Canada did not exist at the time - it was made up of British colonies.

"The US Capitol is more than a building – it is the embodiment of American democracy and our way of life," the historical society said in a statement following the mob siege.

"We are a nation of laws, and the peaceful transfer of power is among the most fundamental hallmarks of our Constitutional republic."