A.
Sheriffs, their under-sheriffs and deputies, constables, marshals and policemen have a duty to suppress unlawful assemblies within their jurisdiction. For that reason they may order all persons who are part of an assembly to disperse. An "unlawful assembly" is an assembly which consists of three or more persons and which causes such a disturbance of public order that it is reasonable to believe that the assembly will cause injury to persons or damage to property unless it is immediately dispersed.
B.
An unlawful assembly includes an assembly of persons who assemble for the purpose of blocking or obstructing the lawful use by any other person or persons of any private or public thoroughfares, property or of any positions of access or exit to or from any private or public building,or dwelling place, or any portion thereof, and which assembly does in fact so block or obstruct the lawful use by any other person or persons of any such private or public thoroughfares, property or any position of access or exit to or from any private or public building or dwelling place, or any portion thereof.