TOWNSEND -- Families with students in the North Middlesex Regional School District have been warned of suspicious activity at bus stops, including an incident where a fifth-grader was approached by an unknown man.

The man is described as a white male with a medium to dark complexion and medium-length black straight hair, wearing silver-framed glasses. He is believed to be between 25 to 35 years old and driving a silver or gray Toyota Prius with tinted windows, Massachusetts license plates and a two-to-four inch blue and white sticker on the back window.

Anyone who sees the vehicle is asked to contact the Townsend Police Department.

The North Middlesex superintendent's office issued an alert to district families last Friday.