SPARWOOD, B.C. -- The search for a three-year-old boy from southeast British Columbia's has gone international, with the Mounties saying they believe the child is in the United States with his father.

Police issued an Amber Alert just after 4 p.m. PDT Thursday for Alvin Barnett, who they believe was abducted by his father, 39-year-old Robert Barnett, in the Elk Valley area near Sparwood.

RCMP Cpl. Dan Moskaluk says police believe Barnett has taken his son into Montana, but he wants British Columbians to remain vigilant and the Amber Alert remains in effect in the province.

According to police, the pair may be travelling in a 2002 blue Subaru Outback with B.C. license 347 SBL.

Alvin is three-feet-two inches tall and 35 pounds, wearing a red shirt and blue jeans, while his father is described as five-foot-five with green eyes, reddish blonde hair and a scar over his right eyebrow.

Police say anyone seeing the pair should not approach them, but should call 911.

Moskaluk said he doesn't know whether or not Barnett holds dual nationality with Canada and the U.S. and what border crossing he may have entered.

"Information was disseminated to our counterparts at the Canadian Border Service Agency and U.S. border crossing points in the Elk Valley area, and at this point in time we do remain in contact with our U.S. law-enforcement counterparts," he said.

Moskaluk said the child and father were together during a supervised parental visit, indicating the father had limited access to his child, and as a result the incident met the criteria for an amber alert.

He said he didn't know why the father may have been on a supervised visit.