TOLEDO, OHIO ? Police began receiving word midweek that gangs were going to descend on a neighborhood where a riot erupted over a planned march by a white supremacist group, but the resulting disturbance was worse than expected, the police chief said Sunday.

The riot broke out Saturday when protesters confronted members of the National Socialist Movement who had gathered at a city park.

Officers who work in the area reported that gang members were planning to turn out in force, and authorities made plans to handle any disturbances, Police Chief Mike Navarre said at a news conference Sunday morning.

“We knew during the preparation that it was going to be a tremendous challenge,” Navarre said. “Anyone who would accuse us of being underprepared I would take exception with that.”

However, he added the protest lasted longer and was more intense than expected.

About two dozen members of the supremacist group, which calls itself “America’s Nazi Party,” had gathered at a city park just before noon Saturday to march under police protection. The march was called off after rioting started.

Authorities want to determine why protesters turned their anger toward police after the Nazi group left, Lucas County Sheriff James Telb said.

People were “highly angry over the idea that someone from outside the community could come in and insult them, Mayor Jack Ford said.

Twelve officers were injured, including an officer riding in her cruiser who suffered a concussion when a brick came through a side window and hit her in the head, Lt. Ron Pfeifer said Sunday.

A state of emergency remained in effect through the weekend. About 200 officers patrolled the neighborhood overnight, Navarre said, and police reported no problems.