Members of the neo-Nazi National Socialist Movement had on Saturday been scheduled to march under police protection through north Toledo, with anti-Nazi groups set to counter-protest.
But police cancelled the event and told the neo-Nazi group to leave as tensions rose and violence erupted nearby, the Toledo Blade reported. The confrontations continued for several hours.
The crowd threw bottles and stones at police, and some officers and firefighters suffered minor injuries, officials said. Police cars and a fire truck were damaged.
"We made about two dozen arrests, but quite frankly could have made a couple of hundred arrests easily," Toledo Police Chief Michael Navarre said.
Police started making arrests after a business was set alight, he said.
"The crowd is temporarily dissipated, that's a good sign, but we are going to have problems here for the next few days," Navarre said. "There will be a very strong police presence in this neighbourhood for several days, as long as it takes."
"There will be a very strong police presence in this neighbourhood for several days, as long as it takes"
Toledo police chief
Toledo mayor Jack Ford blamed the violence on gang members who took advantage of the tensions to settle scores.
"I don't think it was race relations at all. It was some gang members who had real or imagined grievances and took it as an opportunity to speak in their own way over the march, in their park, their area," Ford said.
"That's exactly what [the white supremacist group] wanted," he added.
Navarre said that just about every police officer in the city had been called back to duty and that the Ohio State Patrol had sent officers to help maintain order.
Toledo set an 8pm curfew aimed at people roaming the streets or alleys.