An improvised explosive device has been discovered at the US Capitol building during riots in Washington.

The device was a pipe bomb and was successfully destroyed by a bomb squad, the New York Times reports being told by an official for the Republican National Committee.

It is reported that the device was found at the headquarters of the Republican National Committee (RMC) in Washington and the nearby headquarters of the Democratic National Committee (DMC) was evacuated.

The RNC and DMC are both headquartered a few streets away from the US Capitol which was stormed by a pro-Trump mob chanting unsubstantiated claims of election fraud on Wednesday, January 6.

Supporters of US President Donald Trump clash with police officers

NBC reports that the device "was real and detonated by a bomb squad and harmed no one".

Representative Elaine Luria tweeted: "I just had to evacuate my office because of a pipe bomb reported outside. Supporters of the President are trying to force their way into the Capitol and I can hear what sounds like multiple gunshots.

"I don't recognize our country today and the members of Congress who have supported this anarchy do not deserve to represent their fellow Americans."

Representative Haley Stevens added: "I'm sheltering in place in my office. The building next door has been evacuated. I can’t believe I have to write this."

More than 1,000 members of the US National Guard have been deployed onto the streets of Washington DC in a bid to bring an end to the chaotic scenes.

More than 1,000 members of the US National Guard have been deployed onto the streets of Washington DC

In a pre-recorded video, Donald Trump has called on protesters "to go home now - we have to have peace" as he repeated unsupported claims that the election results were fraudulent.

He said: "I know your pain. I know your hurt. We had an election that was stolen from us. It was a landslide election and everyone knows it, especially the other side.

"But 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 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.

Pro-Trump supporters have stormed Capitol Hill

"This was a fraudulent election, but we can't play into the hands of these people. We have to have peace.

"So go home. We love you. You're very special. You've seen what happens. You've seen the way others are treated that are so bad and so evil.

"I know how you feel. But go home and go home in peace."

Two sources have said one victim is in a critical condition after being shot at the riots, but no further details are available, CNN reports.

Images circulating on social media appear to show a woman with a serious injury to her neck being carried out of the US Capitol building.

There are also reports that multiple police officers have been wounded.

President-elect Joe Biden said that democracy is “under an unprecedented assault” after the pro-Trump supporters stormed the US Capitol building.