FARGO (AP) — Business people and dozens of volunteers began filing into downtown Fargo at dawn Sunday to asses the damage and to clean up after a night of sometimes violent protests over the death of George Floyd in Minneapolis last week.

The protest in North Dakota’s largest city started Saturday with a peaceful march that wound through the city and included parents pushing strollers and teenagers riding skateboards in a tribute to Floyd, a handcuffed black man who died Monday after a white police officer used his knee to pin Floyd’s neck to the ground for several minutes while Floyd pleaded for air and eventually stopped moving.

Like many of the Floyd demonstrations taking place throughout the country, the Fargo protest turned chaotic, with groups of protesters taunting and throwing water bottles at police, who were lined up on a downtown street in riot gear. When police brought out the tear gas shortly before sundown, demonstrators tore through the downtown, smashing restaurant windows, damaging vehicles and holding a bonfire outside the Hotel Donaldson, a popular boutique hotel and bar.

Police were able to keep the most aggressive protesters confined to a roughly four-block area, but that zone included a bank parking lot where many of them retreated to wash their faces with milk to soothe the effects of the tear gas police had used on them.

By the time order was restored, Gov. Doug Burgum and Fargo Mayor Tim Mahoney had both issued state of emergency declarations. Burgum called out the National Guard to help local law enforcement and Mahoney issued a curfew for downtown Fargo that was largely ignored.

“I am extremely disappointed that a peaceful protest has turned into a violent confrontation in the heart of our metro,” Mahoney said Saturday night, echoing civic leaders from many of the other places where protests have been happening that the unrest was the work of “outside influencers who are not reflective of our people.”

At a news conference Sunday, Fargo Police Chief Dave Todd attributed his belief that many out-of-towners were to blame for the unrest to social media reports and undercover officers on the scene who followed some of the violent protesters closely and listened in on their conversations.

Mahoney lauded the people who participated in the peaceful march and urged people to “disavow racism of all forms.”

“We respect the right of people to peacefully protest. Black lives matter. Period. No question,” Mahoney said. “But we do not support anarchy. We do not support vandalism. That is not us and that is not Fargo.”

Todd said his officers attempted to “disengage from protesters” on numerous occasions, but the tipping point was when protesters trapped two officers in a squad car and broke out windows.

Todd said he believed about 50 people came to Fargo solely to “hijack the event.” He said 18 people were arrested, including 10 accused of inciting a riot. Officials said Sunday they weren’t sure where all the people in custody where from, as several listed no permanent addresses. Four officers were treated for injuries, including two who were hit with rocks and bricks and who suffered concussions. Three squad cars were damaged, Todd said.

“There were some very good people still associated with that march trying to stop people from destroying things and stop people from being assaulted,” Todd said.

Burgum, who also spoke at the Sunday news conference, characterized the post-march unrest as an organized riot that was spearheaded by people who “arrived not for dialogue, not for progress, but for violence.”

Among those up early to assess the damage Sunday was the gardener for Gate City Bank, Joan Nicolai, who just planted flowers around the lot last week.

“I’ve been watching things happen throughout the nation, but last night when I heard what was going on here, I just didn’t expect it in Fargo, North Dakota. It seems senseless,” Nicolai said as she picked garbage out of the trampled flowerbeds.

She said she was more concerned about people staying safe than the welfare of her coleus and salvias plants.

“They’re only flowers, right?” Nicolai said.