Antifascists, who refer to the individuals known as the loosely formed organization Antifa, have been labeled as a terror organization.
Antifa, as the name implies, wants to portray itself as being against fascism; however, nothing can be further from the truth. The fact is, they are indeed the fascists, and quite literally, terrorists.
Antifa seems to have somewhat of a long history before becoming a well-financed movement that became anti-government, anti-Constitution, by any means necessary, including arson and murder.
Observing common definitions of fascism and terrorism solidifies their classification of a terrorist organization.
Antifascists.com