Actual members of any organized fire department, whether regular or volunteer, of any municipality shall be vested with police power to form fire lines, to prohibit persons from interfering with firefighters in the discharge of their duties, interfering with apparatus, running over fire hose and trespassing upon private property, and shall have power to blockade any public highway temporarily while in the discharge of their official duties; and for the purpose of effectuating this police power shall have the power to make arrests for violation of any lawful orders made hereunder.