The city, acting by and through its Mayor or Mayor Pro-Tem, or in their absence or inability to act the Chief of Police, may send or direct any of its regularly employed law enforcement officers to assist any other county or municipality when a request is received for assistance from the Mayor or other officer authorized to declare a state of civil emergency in such other municipality or county, representing that there exists in such other county or municipality a need for additional law enforcement officers to protect health, life and property of such other county or municipality or its inhabitants and the visitors thereof, by reason of riot, unlawful assembly characterized by the use of force and violence, or threat by three (3) or more persons acting together or without lawful authority, or during the time of natural or man-made calamity.