U.S. Rep. Ken Buck and 49 other GOP House members wrote to U.S. Attorney General William P. Barr on Thursday imploring him to investigate “these attacks on our republic,” referring to riots and destructive conduct that multiple cities have experienced in association with peaceful racial justice protests.

The “riots in Portland and other major American cities have revealed a targeted effort to destabilize our way of life,” the lawmakers wrote. “It is readily apparent that these individuals were outfitted for war and were clearly a part of a planned effort to infiltrate peaceful protests, provoke violence, and further subvert our system of government.”

Buck, who is also the chair of the Colorado Republican Party, subsequently tweeted that “left-wing anarchist groups” have perpetrated “totalitarian attacks,” and suggested a need to investigate the funding of such groups. The GOP representatives’ letter specifically addressed “ANTIFA,” which is an abbreviation for anti-fascist. The term indicates an ideology, rather than an organized membership group.

The letter referenced the August shooting of Aaron J. Danielson in Portland during a clash of protesters in the city. The lawmakers described Danielson as “a supporter of President Trump,” while The Washington Post reported he was a member of a right-wing group that Facebook has removed from its platform in a crackdown on “violent social militias.” Police since killed the man accused of murdering Danielson.

Among the other reasons the lawmakers cited for investigating rioters were the burning of buildings, “stealing livelihoods,” and “accosting a sitting U.S. Senator,” an allusion to the protesters who followed U.S. Sen. Rand Paul, R-Ky. after the Republican National Convention and drawing attention to the killing of Breonna Taylor in his home state.