A former Canadian Armed Forces reservist from Manitoba linked to a violent white supremacist group has been denied bail following his arrest in the US.

A judge in Maryland who ordered Patrik Mathews detained pending a preliminary hearing on felony charges described him as a "very dangerous person'' who "espouses very dangerous beliefs.''

A prosecutor says Mathews and two other men arrested last Thursday were preparing "essentially a paramilitary strike'' at the gun rights rally in Richmond January 20, 2020, in hopes it would start a civil war.

Mathews disappeared from his base in Winnipeg last summer after it was reported he was a recruiter for a military white supremacist group called The Base.