The Department of Homeland Security and the FBI sent a joint intelligence bulletin to state and local law enforcement agencies late Tuesday warning that some domestic groups have "discussed plans to take control of the U.S. Capitol and remove Democratic lawmakers on or about" March 4, according to a senior law enforcement official who described the document to NBC News.
The bulletin, titled "National Capital Region Remains Attractive Target for Domestic Violent Extremists," warned that "Domestic Violent Extremists" or "Militia Violent Extremists" were emboldened by the Jan. 6 attack on the U.S. Capitol and therefore pose a higher overall threat.
The bulletin said the militia violent extremists may "exploit public gatherings either formally organized or spontaneous to engage in violence," according to the description of the document.
It also states that domestic violent extremists have a continued "perception of election fraud and other conspiracy theories associated with the presidential transition, which may contribute to (Domestic Violent Extremists) mobilizing to violence with little or no warning."
The law enforcement official said the bulletin makes clear that "the threat did not begin or end on January 6."
On Wednesday, the U.S. House abruptly scrapped plans to meet Thursday and began finishing its work for the week given the threat of violence.
House Majority Leader Steny Hoyer notified lawmakers late Wednesday of the sudden schedule change.
The House had been scheduled to be in session Thursday, but moved up consideration of its remaining legislative item, the George Floyd Justice in Police Act, to Wednesday night.
The Senate had not altered its schedule.
The new warning comes as national security officials testified before two Senate committees about the law enforcement response to the Capitol assault in January.
A DHS spokesperson said the threat from domestic violent extremism, "particularly racially-motivated and anti-government extremists, did not end on January 6 or Inauguration Day."
"We are witnessing a years-long trend of false narratives fueling violence, and the current heightened security environment in the National Capital Region illustrates that this will be an ongoing challenge for law enforcement in the months to come," the spokesperson said.
Download the NBC News app for breaking news and politics
Also Wednesday, the Capitol Police said it has obtained intelligence showing a “possible plot to breach the Capitol by an identified militia group” March 4.
“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 agency said in a statement.
Supporters of the QAnon conspiracy theory have set March 4 as the date they believe former President Donald Trump will return to office.
NBC News reported Tuesday that law enforcement agencies around Washington were adding extra security out of concerns about potential unrest. While users in online QAnon groups are looking forward to Thursday, no specific protests or events are being planned, according to an NBC analysis of the largest remaining forums.