"We do not want you here. We do not need you here. Just stay away," Antaramian said.
On Thursday night, the Kenosha Police Department reported that officers had arrested nine people in vehicles with out of state license plates who were equipped with gas masks, helmets, fireworks and vests.
Wisconsin National Guard commander Maj. Gen. Paul Knapp told the press conference he had 1,000 guardsmen currently deployed in the city of 100,000 people and would stay there "as long as we are needed."
Kyle Rittenhouse, a teenager who killed two protesters and seriously wounded a third on Tuesday, said in an interview for social media earlier that he had arrived armed with a rifle to help locals protect their property from rioters. Rittenhouse surrendered to the authorities after the incident on Tuesday night.
Riots ignited in Kenosha and other US cities after police was called to the scene of a domestic incident on Sunday when they shot in the back African American Jacob Blake seven times.
In May, the authorities had accused Blake of unlawfully entering a home and sexually assaulting a woman before leaving with her vehicle, according to media reports.
Blake underwent several surgeries and is recovering in a local hospital. Blake's attorney said on Friday that a warrant against his client has since been vacated.