US says more than 300 people charged to date over Capitol riots

The US Justice Department has charged more than 300 people with taking part in the deadly storming of the Capitol by former President Donald Trump's supporters, and at least 280 have been arrested, Acting Deputy Attorney General John Carlin told reporters on Friday.

"The investigation into those responsible is moving at a speed and scale that's unprecedented, and rightly so," he said. "Those responsible must be held to account, and they will be."

Read more: Capitol riot costs will exceed $30 million, official tells US Congress

His comments came just one day after Capitol Police Acting Chief Yogananda Pittman told lawmakers that Trump supporters had indicated they may wish to blow up the building. Pittman expressed concern extremists could target Congress during an address by President Joe Biden.

A senior FBI official, responding to questions about that threat on Friday, said the bureau is "watching very closely for any reaction from individuals that would show either an intent to commit an attack or somebody that has already committed one."