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As in the past, Seattle police anticipated the actions of self-proclaimed anarchists on May Day. But the Seattle Police Department’s incident commander for the protests said this year was notably different.

“I was surprised at the numbers of people at Seattle Central (Community College) that wanted to get into a confrontation,” Captain Chris Fowler told

KIRO Radio’s Jason Rantz. “I have not seen that many black bloc anarchists — people dressed up in that vein — that wanted to cause problems that early.”

Related: Mayor, chief praise police response to violent May Day protest in Seattle

“I would say that it was a substantial difference between the small groups of people that wanted to commit violence from years past, or the small groups that we’ve seen glom onto peaceful protest,” Fowler said. “This was a group of people in a large group — 75, 100, 200 mixed into a crowd of much larger size — that facilitated that violence and destruction.”

What is to blame for the uptick, Rantz asked.

“I don’t know if it’s just levels of frustration or there was a need to make some sort of statement,” Fowler said. “Clearly, they were out to commit violence and crime. So it’s hard for me to relate to people that want to do that. It’s hard to say.”

Officers confiscated a hammer, wrenches, batteries, and a machete with “death” written on it. A total of 17 arrests were made Friday night. Three officers went to the hospital for injuries. Rioters smashed over 20 cars, including a KIRO Radio truck.

Photos from May Day protests

As in years past, the Seattle Police Department is expected to release photos and ask people to help identify rioters for further arrest.

Fowler said the department still has a lot of video and photos to look through, and that the investigation is underway.

He noted that just because they arrest someone, it doesn’t mean that they will eventually be charged. That is up to prosecutors, he said. In the meantime, police are making arrests for a range of crimes from felony assault to obstructing.

After the protest-turned-riot, Fowler said that he knew those crimes were likely coming as he watched the anarchist crowd gather.

“When they left Seattle Central Community College and moved down Broadway, it was relatively peaceful, but we knew before they left that there were going to be issues,” Fowler said. “You could hear the crowd talk about what they were going to do as you were standing there. You saw the sticks, you could see them putting wrenches into their sleeves. It was unlike anything I had seen before.”

The Seattle Police Department is expected to brief the Seattle City Council Wednesday afternoon about the actions officers took on May 1.