Police in Hamilton say they are concerned for the safety of a 13-year-old boy who went missing more than a week ago.

According to investigators, 13-year-old Arnold Knelsen was last seen in the Hamilton Mountain area on July 31.

Police say the teen is approximately five-foot-three and weighs about 100 pounds. He has a thin build and short, light brown hair.

Anyone with information on Knelsen’s whereabouts is asked to call the Hamilton Police Service at 1-800-222-8477.