MADISON, Wis. - A weekend of Halloween celebrations popular with college students resulted in more than 400 arrests, and police used bursts of pepper spray early Sunday to break up crowds of revelers.

Mayor Dave Cieslewicz suggested canceling the annual gathering. The downtown party near the University of Wisconsin-Madison attracts college students from across the Midwest, and has turned chaotic in the past. Last year, 455 were arrested.

Most arrests were for alcohol-related offenses, including underage drinking, said Lt. Pat Malloy. He said the local detoxification center was filled to capacity and some people had to be taken to emergency rooms.

The university had taken steps to control the chaos this year, prohibiting visitors from dormitories and warning Big 10 and other Midwest schools that students shouldn't come. City officials and the university have said most of the problems are caused by out-of-town visitors.