Trump supporters who clashed with police as they broke into the US Capitol are ‘militia violent extremists’ and advocate for white supremacy, FBI director Chris Wray has testified.

Speaking before the Senate Judiciary Committee for the first time in almost two years, he labelled the Capitol insurrection on January 6, which resulted in five fatalities, “domestic terrorism”.

“It’s behaviour that we, the FBI, view as domestic terrorism. It’s got no place in our democracy and tolerating it would make a mockery of our nation’s rule of law,” Mr Wray said on Wednesday morning (Australian time).

“The problem of domestic terrorism has been metastasising across the country for a long time now and it is not going is a way any time soon,” he continued.

Mr Wray said it was an issue the FBI had warned about for years.

“I’ve been sounding the alarm about domestic terrorism since I think just about my first month on the job,” he said.

He said the FBI has seen “quite a number of what would we call militia violent extremists” and specifically mentioned the groups the Proud Boys and Oath Keepers.

The people who attacked the Capitol were also “racially motivated violent extremists” who advocated for white supremacy, Mr Wray said.

“One of the things that is happening as part of this is that as we build out the cases on the individuals when we arrest them for the violence, we’re getting a richer and richer understanding of the different people’s motivations,” he said.

“But certainly as I said, militia violent extremism and some instances of racially motivated violent extremism, especially advocating for the superior of the white race.”

Christopher Wray during his testimony to the Senate Judiciary Committee. Photo: AAP

Mr Wray was defending the bureau’s handing of intelligence indicating that there might be violence on January 6.

He said the bureau immediately shared with other agencies a report that included “raw and unverified” intelligence predicting the attack.

A January 5 report from the FBI’s field office in Norfolk, Virginia, warned of online posts foreshadowing a “war” in Washington DC the following day.

The former chief of the Capitol Police and others have said the information wasn’t flagged for them and was sent only in an email.

Mr Wray said he did not see the report until after the attack but it was shared properly.

Meanwhile, former White House press secretary Kayleigh McEnany told Fox News that she expected a peaceful protest.

“I think at the beginning of the day, before everyone went to the rally, everyone was expecting peace,” Ms McEnany said.

“We had been to hundreds of rallies – I’ve probably been to hundreds at this point, certainly many dozens – and they were nothing but peaceful events, and we expected that day to be the same.

“Then as those events transpired, it was disbelief, shock, somber, sad, horrified by the violence, and it was a very hard, difficult day in the White House, there is no doubt.”

-with AAP