The US should brace for more civil unrest this year in wake of the deadly riots at the US Capitol, according to a new warning from federal officials who say the extremists responsible pose “the greatest domestic terrorism threat of 2021.”

A Joint Intelligence Bulletin by the Department of Homeland Security, FBI and National Counterterrorism Center says the insurrection at the nation’s capital will only “embolden” the “domestic violent extremists” that carried out the attack and unify them.

“In 2021, threats and plotting of illegal activity, including destruction of property and violence targeting officials at all levels of the government, law enforcement, journalists, and infrastructure, as well as sporadic violence surrounding lawful protests, rallies, demonstrations, and other gatherings by DVEs will very likely increase due to renewed measures to mitigate the spread of COVID-19, socio-political conditions, and perceived government overreach,” the memo, released Wednesday, warns.

The official document, first reported by Yahoo News and uploaded online, notes potential collaboration among extremists from different ideologies — especially after the fatal shooting of QAnon enthusiast Ashli Babbitt, whose death is being treated as “an act of martyrdom.”

Babbitt was one of four people killed in Wednesday’s insurrection, including Capitol Police officer Brian Sicknick.

Still, the feds warned that the rioters likely perceive the revolt as a success — which poses a serious security threat to federal, state and local governments in the days leading up to the Jan. 20 inauguration of President-elect Joe Biden.

The memo said the extremists feel united over the shared sentiment that the election was “stolen” — and may be susceptible to joining the Boogaloo movement, a far-right conspiracy theory that the US is on the brink of a second Civil War.

Minority groups may also be at risk of attacks by extremists looking to spark a “race war” by exploiting “the aftermath of the Capitol breach by conducting attacks to destabilize and force a climactic conflict in the United States,” the feds said.

The memo mentions other acts of violence on Capitol grounds from Jan. 6 — including two explosive devices that were left outside the Republican and Democratic national committees’ headquarters and nooses and plastic restraints carried by rioters “possibly to demonstrate their intent to cause harm to government officials.”

Rioters also threatened members of the media, breaking cameras and other equipment, the document said. “Murder the media” was found scratched into a door inside the Capitol building.

Dozens of rioters have been arrested on various charges so far — though officials have vowed to bring charges against hundreds.

The FBI has warned that more protests are planned in all 50 states ahead of Inauguration Day — fueled by outrage over the second impeachment of President Trump for allegedly inciting the Capitol riots.