Dozens of people charged in connection with the violence are members of the far-right Proud Boys and Oath Keepers.

The U.S. Department of Justice has accused more than 300 people of participating in the deadly assault on the Capitol by supporters of former President Donald Trump and at least 280 have been arrested, Acting Assistant Attorney General John Carlin told reporters on Friday.

“The investigation into those responsible is proceeding at a speed and scale that is rightly unprecedented,” said Carlin. “Those responsible must be held accountable, and they will be.”

On Thursday, the Acting Police Chief of the Capitol, Yogananda Pittman, told lawmakers that Trump supporters had indicated they might want to blow up the building. Pittman expressed concern that violent groups might target Congress during a speech given by President Joe Biden.

On Friday, a senior FBI official responded to questions about the threat that the office is “paying close attention to reactions from either those who intend to commit an attack or someone who has already committed one”.

The FBI has been investigating whether fringe right-wing groups such as the Oath Keepers and Proud Boys conspired in advance to obstruct the election certification.

So far, at least 18 Proud Boys employees have been charged in connection with the unrest. This month, prosecutors accused nine oath guards workers in connection with an alleged conspiracy to storm the Capitol as early as November 2020.

The senior FBI official told reporters that domestic extremists have been an increasingly serious threat for several years and that anti-government extremist threats will be and remain a top concern in 2020.

“2020 was a very big year for us. The violent reaction to a mix of events across the country is unlike anything we’ve seen in decades, “the official said, noting that three of the four fatal attacks in the country came from people who belonged to an” anti-government ” ascribe or violent extremist ideology against authority ”.