Northern Minnesota residents have been cautioned to be on the lookout for a Canadian army reservist suspected of having links to a neo-Nazi group that has advocated violence.

In a Facebook post, the Roseau County Sheriff’s Office said that Patrik Jordan Mathews’ vehicle was found abandoned near Sprague, Manitoba, on Monday, just north of the Minnesota-Canadian border. “DO NOT APPROACH” him, the post warned, adding that anyone who sees him should contact the Sheriff’s Office at 218-463-1421 or the U.S. Border Patrol at 701-775-6259.

According to an article posted by the Sheriff’s Office from the Global News Canada website, Mathews was last seen by family members on Aug. 24. He disappeared after the Winnipeg Free Press reported that he was under investigation by the military and the Royal Canadian Mounted Police (RCMP) for allegedly recruiting members for a white supremacist network called the Base that focuses on future “race wars.”

The RCMP seized a number of firearms from a home he was associated with in Beausejour, Manitoba, after the Free Press report, Global News reported. A Canadian army reserve spokesman told the paper that Mathews has been suspended from his military duties, that he previously had requested a voluntary release from those duties and had returned all of his military weapons.

According to the publications, Mathews, a master corporal, worked as a combat engineer and is trained in the use of explosives.

Mathews, while under investigation, has not been charged with any crime, the publications said. For now, his case is being treated as a missing-person report.