ORS 131.675: Dispersal of unlawful assemblages.

When any five or more persons are unlawfully assembled in any county, city, town or village, the sheriff of the county and the deputies of the sheriff, the mayor of the city, town or village, or chief executive officer or officers thereof, may go among the persons assembled, or as near to them as they can with safety, and command them in the name of the State of Oregon to disperse. If, so commanded, they do not immediately disperse, the officer may arrest them or cause them to be arrested for any unlawful activity constituting an offense.