Elgin Police Chief Jeffrey Swoboda says the fight started shortly after 10 a.m. when the parade began.
He was at the head of the town's parade, riding in police department vehicle and jumped out to respond. He tackled one of the suspects involved in the fight.
Two men were transported to an area hospital in unknown conditions, Fire department spokesman Tim Michaels said.
Information on the arrests wasn't immediately available.
The altercation didn't affect the parade.