Police used repeated bursts of pepper spray early Sunday to break up a crowd of Halloween celebrants, part of a weekend of revelry in which more than 400 people were arrested.
No serious injuries or property damage were reported.
Police declared an unlawful assembly early Sunday in Madison, Wisconsin, and used officers on horseback to move chanting and beverage-tossing revelers off the streets. The pepper spray was used after cups filled with beverages and ice were thrown at officers.
Most arrests were for alcohol-related offenses, said Lt. Pat Malloy. He said the local detoxification center was filled to capacity and some people had to be taken to emergency rooms.
There were 269 arrests overnight and 178 the night before, Police Chief Noble Wray said.
Madison is the home of the University of Wisconsin-Madison.
Elsewhere, police in Athens, Ohio, home of Ohio University, made 95 arrests at a Saturday night Halloween block party. Police described the crowd as belligerent but smaller than in previous years. Forty-eight of those arrested are college students, officers said.
One man was stabbed in the hand and a woman was injured escaping from an attempted rape, Athens police spokesman James Mann said, AP reported. V.A.