The U.S. Justice Department (DOJ) has charged over 300 people in connection with the deadly Jan. 6 Capitol riot by pro-Trump supporters, acting Deputy Attorney General John Carlin told reporters Friday.

The DOJ official said the investigations into those who attacked the Capitol were moving "at a speed and scale that’s unprecedented, and rightly so."

"Those responsible must be held to account, and they will be," he said, adding that at least 280 people have also been arrested in addition to the charges.

HOUSE REPUBLICANS TELL PELOSI CAPITOL FENCING ERECTED AFTER RIOT NEEDS TO COME DOWN

Carlin’s announcement comes just one day after Capitol Police Acting Chief Yogananda Pittman told lawmakers that "militia groups" present during the Jan. 6 attack have indicated they may try and "blow up" the building at some point in the future, when President Biden addresses Congress.

"We know that members of the militia groups that were present on Jan. 6 have stated their desires that they want to blow up the Capitol and kill as many members as possible with a direct nexus to the State of the Union, which we know that date has not been identified," Pittman told the House Appropriations Subcommittee on the Legislative Branch Thursday.

A senior FBI official said the agency will be watching the threat "very closely for any reaction from individuals that would show either an intent to commit an attack or somebody that has already committed one."

The official said that domestic terrorism has become an increasing problem in the U.S. since 2019, which was the deadliest year in domestic terror attacks since the Oklahoma City Bombing in 1995.

Last year saw its fair share of violence, with 180 cases of domestic terrorism.

"The violent reaction to a mixture of events that took place around the country is unlike anything we have seen in decades," the FBI official said.

The deputy attorney general stressed the importance of "information sharing" and said it is a practice that helps security officials "collectively respond to present and emerging domestic threats."

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But when pressed by Fox News about the apparent lack of communication between the FBI and Capitol Police in the lead up to the Jan. 6 attack, officials from the DOJ and FBI who were briefing reporters sidestepped the question.

"I will just say, we have processes in place for sharing information," the senior FBI official said. "We continue to grow our partnerships and the sharing of our information beyond state and local and federal partners." 

 Danielle Wallace contributed to this report.