FILE - In this Wednesday, Jan. 6, 2021 file photo, Trump supporters try to break through a police barrier at the Capitol in Washington.
In contrast, the deadly attack by rioters on the U.S. Capitol targeted the very heart of government.
It brought together members of disparate groups, creating the opportunity for extremists to establish links with each other.
The document singles out crimes motivated by racial or ethnic hatred, such as the 2019 rampage targeting Hispanics in El Paso, Texas, as well as the threat posed by extremists motivated by foreign terror groups.
The alert comes at a tense time following the riot at the Capitol by supporters of then-President Donald Trump seeking to overturn the presidential election.