The FBI chapter based in Phoenix, Arizona, is investigating so-called “anarchist extremists” who’ve been protesting the conditions at the migrant detention centers along the southern border.

According to an FBI document obtained by Yahoo News, the bureau is tracking what it calls “anarchist extremists” (or “AEs”) and their opposition to immigration officials’ treatment of migrants.

FBI Phoenix labels the groups as a “growing threat” in Arizona, citing “increases in public anti-government demonstrations,” “discussing, planning, or implementing firearms training,” and “rhetoric” against the governments’ actions at the border.

However, the document doesn’t cite any violent actions that have taken place; rather, it claims that the “threat” will “likely grow in intensity and frequency in the near to mid-term.”

“These products are intended to be informative in nature, and as such, they contain appropriate caveats to describe the confidence in the sourcing of information and the likelihood of the assessment,” an FBI spokesperson told Yahoo News. “Additionally, when written at a local level, these products will note that the perspective offered may be limited to the field office’s area of responsibility.”

Read the memo obtained by Yahoo News: