If any building or structure shall be erected, constructed, reconstructed, altered, repaired, converted or maintained, or any building, structure or land used in violation of this act, or of any ordinance or regulation made under authority hereof, the person or persons, artificial or natural, knowingly so offending, shall be subject to a fine of not more than one thousand ($1,000.00) dollars, and not less than one hundred ($100.00) dollars, as prescribed by the council of any such city to be recovered as fines and penalties of like amount are now recoverable by law. The fact of such violation being committed shall be prima facie evidence that it was knowingly done. In case of any such actual or threatened violation, either the said city, or the bureau officer or official designated for the enforcement of any ordinance passed by virtue of this act, may institute any appropriate action or proceeding to prevent or abate such unlawful erection, construction, reconstruction, alteration, conversion, maintenance, use or occupation, or to restrain or prevent any illegal act or business or use, under this act, or under any such ordinance or regulation.