It shall be the duty of the mayor of a city of the metropolitan class to:
(1) Enforce the laws of the state and the ordinances of the city;
(2) Order, direct, and enforce, through the officers of the police department, the arrest and prosecution of persons violating such laws and ordinances; and
(3) Cooperate with and assist the county sheriff in suppressing riots and mobs and in the arrest and prosecution of persons charged with crimes.