Violence has erupted in Washington DC as supporters of President Donald Trump storm the US Capitol Building, with reports of a woman being shot.

Law enforcement officers inside the House of Representatives chamber have drawn their guns and trained them on the doors of the chamber where Trump supporters are trying to break through.

ABC News has reported shots fired inside the building and CNN reports a woman is in critical condition after being shot in the chest on the Capitol grounds. Virginia is sending the National Guard and 200 state troopers to Washington DC at the mayor's request, Reuters reports.

US Capitol Police with guns drawn defend House Chamber. Photo / AP

President-elect Joe Biden called on Trump to "go on television now to defend his oath and demand an end to this seige".

Biden said the protesters do not represent America and that the invasion of the Capitol "borders on chaos, borders on sedition and it must end now," he said.

"Today is a reminder, a painful one. Democracy is fret, and to preserve it requires people of good will - leaders with the courage to stand up."

Shortly after, Trump posted a video to Twitter in which he asked his supporters to "go home and go home in peace".

"We have to have law and order and we have to respect our great people in law and order."

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pic.twitter.com/Pm2PKV0Fp3

— Donald J. Trump (@realDonaldTrump) January 6, 2021

Earlier, Congress members were forced to leave the building, leaving gas masks on their desks, as the Capitol went into lockdown in response to the siege.

The protesters are attempting to stop Congress from affirming President-elect Joe Biden's victory in the November presidential election. Congress was due to officially count the Electoral College votes - normally a formality - this morning (NZT).

With the Washington Monument in the background, people attend a rally in support of President Donald Trump near the White House. Photo / Jacquelyn Martin, AP

A woman is in critical condition after being shot in the chest on the Capitol grounds, according to two sources familiar with the matter. The sources could not provide further details on the circumstances of the shooting.

Vice President Mike Pence was also evacuated from Capitol, where he was to perform his role in the counting of electoral votes.

Video from inside the Capitol showed Trump supporters marching through Statuary Hall. The US Capitol Police is asking for additional law enforcement for assistance, including federal authorities, per a source familiar.

The source says there are several suspicious devices outside the Capitol building.

House and Senate leadership is safe and in an undisclosed locations, according to a person familiar. A separate lawmaker said House members have been evacuated to a location that this source would not disclose.

Everything in the Senate just stopped after an aide just whispered “protestors are in the building” pic.twitter.com/qR2gSokK5v

— philip lewis (@Phil_Lewis_) January 6, 2021

The US Capitol Police are working to secure the second floor of the Capitol first, and will then expand from there. Outside the Capitol, the DC Metropolitan Police Department continues to mass, but no major move has been made yet toward the crowd.

The Capitol police officer in the House chamber told lawmakers that they may need to duck under their chairs and informed lawmakers that protesters were in the building's Rotunda. Lots of House members were seen wearing gas masks as they move between Capitol buildings. Members were calling family to say they are OK.

The violence and destruction taking place at the US Capitol Must Stop and it Must Stop Now. Anyone involved must respect Law Enforcement officers and immediately leave the building.

— Mike Pence (@Mike_Pence) January 6, 2021

While the White House refused to comment on the protests, Trump said on Twitter, "Please support our Capitol Police and Law Enforcement. They are truly on the side of our Country. Stay peaceful!"

Others inside the President's orbit tweeted their calls for calm as the mob repeatedly attempted to take over the building.

Donald Trump Jr., the President's son, said that his supporters who mobbed the Capitol were "wrong and not who we are."

"Be peaceful and use your 1st Amendment rights, but don't start acting like the other side. We have a country to save and this doesn't help anyone," he tweeted.

The protesters have breached exterior security barriers, and video footage shows protesters gathering and some clashing with police near the Capitol building. CNN's team on the ground saw a number of protestors trying to go up the side of the Capitol building. Several loud flash bangs have been heard.

I am in the House Chambers. We have been instructed to lie down on the floor and put on our gas masks. Chamber security and Capitol Police have their guns drawn as protesters bang on the front door of the chamber.

This is not a protest. This is an attack on America.

— Rep. Dan Kildee (@RepDanKildee) January 6, 2021

Protesters could be seen pushing against metal fences and police using the fences to push protesters back, while other officers reached over the top to club people trying to cross their lines.

Flash bangs could be heard near the steps of the Capitol as smoke filled the air. In some instances officers could be seen deploying pepper spray. Tear gas has been deployed, but it's not clear whether by protesters or police, and people wiped tears from their eyes while coughing.

I am safe. We have been evacuated.

Let me be clear: we will not be stopped by this lawless intimidation. pic.twitter.com/WWDJst4V1B

— Rep. David Trone (@RepDavidTrone) January 6, 2021

Washington Mayor Muriel Bowser just announced a citywide curfew from 6 p.m. ET on Wednesday until 6 a.m. ET Thursday.

Federal and local law enforcement are responding to reports of possible pipe bombs in multiple locations in Washington DC, according to a federal law enforcement official. It's unclear if the devices are real or a hoax, but they're being treated as real.

text by Ted Barrett, Manu Raju and Peter Nickeas, CNN