A primary city shall have power to regulate, license or suppress halls, opera houses, churches, places of amusement, entertainment or instruction or other buildings used for the assembly of citizens. It may cause them to be provided with sufficient and ample means of exit and entrance, and to be supplied with necessary and appropriate appliances for the extinguishment of fires and for escape from such places in case of fire. It may prevent overcrowding and regulate the placing of seats, chairs, benches, scenery, curtains, blinds, screens or other appliances therein. It may provide that for any violation of any such regulation a penalty of not to exceed two hundred dollars shall be imposed, and that upon the conviction of any violation of any ordinance regulating such places, the license of such place shall be revoked by the mayor and council. Whenever the mayor or council shall by resolution declare any such place to be unsafe, the license thereof shall be thereby revoked; and the council may provide that in any case where they have so revoked the license, any owner, proprietor, manager, lessee or person, opening, using or permitting such place to be opened or used, involving the assembling of more than twelve persons, shall upon conviction thereof be deemed guilty of a misdemeanor and fined in any sum not exceeding two hundred dollars.