Section 13I. Whoever commits an assault or assault and battery on an emergency medical technician, an ambulance operator, or an ambulance attendant, while said technician, operator or attendant is treating or transporting, in the line of duty, a person, shall be punished by imprisonment in the house of correction for not less than ninety days nor more than two and one-half years, or by a fine of not less than five hundred nor more than five thousand dollars, or both.