wellesenterprises/iStockBy JACK DATE, LUKE BARR and MORGAN WINSOR, ABC News

(WASHINGTON) — U.S. Capitol Police officials said Wednesday they have “obtained intelligence that shows a possible plot to breach the Capitol by an identified militia group on Thursday, March 4” — the date that far-right conspiracy theorists believe former President Donald Trump will return to power.

The intelligence, which an FBI bulletin said could involve the “Three Percenters” group prosecutors call “extremist,” is being taken “seriously,” the Capitol Police officials said in a statement posted on Twitter.

“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 statement said. “Our Department is working with our local, state, and federal partners to stop any threats to the Capitol. We are taking the intelligence seriously. Due to the sensitive nature of this information, we cannot provide additional details at this time.”

The Capitol complex remains surrounded with temporary fencing topped with razor wire and some 5,000 National Guard troops remain on site.

The statement issued Wednesday morning follows another Tuesday night in which officials said they had beefed up security.

“The Department is aware of concerning information and intelligence pertaining March 4th and continues to work with all of our law enforcement partners,” the federal law enforcement agency said in that statement. “Based on the intelligence that we have, the Department has taken immediate steps to enhance our security posture and staffing for a number of days, to include March 4th. The Department has communicated our enhanced posture as well as the available intelligence for the entire workforce.”

An internal U.S. Capitol Police bulletin distributed Tuesday contains information about a possible militia plot to storm the Capitol on or around March 4, sources told ABC News.

The information in the bulletin is sourced to an FBI intelligence report from late February that describes the an alleged plot by the “Three Percenters militia group to use diversionary tactics such as detonating a bomb” to draw law enforcement away from the Capitol prior to an attempt by the group to take over the U.S. Capitol, according to a law enforcement source.

The credibility of the information in the bulletin remains unclear.

The bulletin describes the Three Percenters alleged goal of having 50,000 members from around the country travel to D.C. on our around March 4 through March 6 and participate in a plan to overrun law enforcement and the National Guard troops at or near the Capitol Complex, the source said.

Federal prosecutors have described Three Percenters in court as a “militia extremist” group “based on the myth that only three percent of American colonists took up arms against the British during the American Revolution,” and that some members “regard the present-day US Government as analogous to the British” during the American Revolution in terms of infringements on civil liberties.

While there are many independent groups that use “Three Percenters” in their name, prosecutors say the term is “representative of a common belief in the notion that a small force with a just cause can overthrow a tyrannical government if armed and prepared.”

An FBI spokesperson did not immediately comment on the intelligence information.

One law enforcement source said that initial intelligence does not support a crowd of 50,000 is coming to Washington, D.C. this week.

News of the Capitol Police bulletin was first reported by the local news station WTTG in Washington, D.C.

Sources tell ABC News that intelligence chatter surrounding the date of March 4 has been circulating for weeks. The date has significance for adherents to the QAnon conspiracy theory who believe it is the day former President Donald Trump will return to power. March 4 is also the original date for presidential inauguration in the Constitution, prior to the ratification of the 20th Amendment in 1933 that changed it to Jan. 20.

How U.S. law enforcement and intelligence agencies missed the violent insurrection on January 6 has been the focus of multiple congressional inquiries in recent weeks.

FBI Director Chris Wray, in testimony on Capitol Hill, Tuesday, told lawmakers how an intelligence information gathered by the FBI in Norfolk, Virginia, warning of possible violence at the Capitol on January 6 was shared with law enforcement partners, including the U.S. Capitol police on the evening of January 5.

A possible source of the threats is QAnon, the umbrella term for a set of disproven and discredited internet conspiracy theories that allege the world is run by a secret cabal of Satan-worshipping cannibalistic pedophiles. Followers of the fringe movement believe that the 2020 U.S. presidential election was stolen from Trump, who has pushed baseless claims of voter fraud along with his allies.

QAnon followers also believed that Trump would not actually leave office on Inauguration Day but rather would declare martial law, announce mass arrests of Democrats and stop Joe Biden from becoming president. When that didn’t happen, the date was moved from Jan. 20 to March 4.

The Federal Bureau of Investigation first labeled QAnon and its fluid online community of supporters as a “dangerous extremist group” in August 2019. A number of individuals believed to be QAnon followers have been charged for their alleged involvement in the deadly insurrection on Jan. 6, when pro-Trump supporters stormed the U.S. Capitol building in Washington, D.C.

On Monday, the U.S. Department of Homeland Security’s Office of Intelligence and Analysis issued a confidential assessment to law enforcement agencies, which was obtained by ABC News, saying that the threat of domestic violent extremism in 2020 — largely driven by “violent anti-government or anti-authority narratives, periods of prolonged civil unrest and conspiracy theories” — is a trend that will likely continue in 2021 and “could escalate to include targeting of critical infrastructure.”

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