Section 5A. Independent vocational-technical schools may be established under sections fourteen and fifteen of chapter seventy-one, if the agreement for the establishment of the regional school district, either as originally adopted or as subsequently amended, so provides, and for that purpose the regional district school committee shall have the powers and perform the duties conferred or imposed by law upon local trustees for vocational-technical education, and may be known as a board of regional school district trustees for vocational-technical education.