US police on Wednesday said they have enhanced security after intelligence uncovered a "possible plot" to breach the US Capitol on March 4 —  a day far-right conspiracists believe Donald Trump will rise to power again.

"We have obtained intelligence that shows a possible plot to breach the Capitol by an identified militia group on Thursday, March 4," the US Capitol Police said in a statement.

"We have already made significant security upgrades to include establishing a physical structure and increasing manpower to ensure the protection of Congress, the public and our police officers," the police force said, adding it is "taking the intelligence seriously."

The threat from an identified militia group comes almost two months after Trump supporters, including QAnon followers, stormed the Capitol building and laid siege to Congress. Five people died in the attack.

What is the meaning of March 4?

March 4 marked the original presidential inauguration day until 1933, when it was moved to January 20.

Some QAnon followers believe Trump was cheated out of a second term and that on Thursday he will rise to confront supposedly Satanist liberals.  

What remained unclear Wednesday is whether the threat by the militant group is limited to online talk by extremists, or whether groups and individuals plan to head to Washington.

US can 'expect racially violent extremists'

Testifying to Congress on Wednesday, Jill Sanborn, FBI assistant director of counterterrorism, said the US can "expect racially or ethnically motivated violent extremists, anti-government or anti-authority violent extremists."

She added that "other domestic violent extremists citing partisan political grievances will very likely pose the greatest domestic terrorism threats in 2021 and likely into 2022."

According to the Federal Bureau of Investigation, cases of domestic extremism in the US have spiked significantly in recent years.

Various law enforcement agencies and Capitol police attended hearings this week on their handling of the January 6 attack. Trump supporters in tactical gear smashed into the building, temporarily hindering Congress' certification effort and prompting lawmakers into hiding.

The National Guard, deployed hours after the storming, continues to monitor the Capitol as part of heightened security measures.

mvb/aw (AP, AFP)