Authorities in northwestern Minnesota are on the lookout for Patrik Mathews, a missing, Canadian soldier who is believed to have crossed the border this week.

Both the Roseau and Kittson County Sheriff’s Offices and U.S. Border Patrol are on alert for Mathews who was relieved of his military duties over allegations of his involvement with neo-Nazis. His pickup was found abandoned just a few miles north of the U.S. border, not far from Roseau earlier this week. It’s believed the 26-year old walked across the border into Minnesota. Canadian authorities say Mathews is an army reservist with a Winnipeg-based brigade who worked as a combat engineer and is trained in the use of explosives and should not be approached. Canadian reports claim Mathews was recruiting for a white supremacist network called The Base, which operates out of the U.S.