Authorities in Atlanta say 35 people have been detained after a violent protest erupted at the site of a new police training center.

Police Chief Darin Schierbaum said at a midnight press conference that several pieces of construction equipment were set on fire at the site for the Atlanta Public Safety Training Center in DeKalb County.

Local media reports show flames rising from the site. The Atlanta Journal Constitution, citing police, reported that protesters dressed in all black threw large rocks, bricks, Molotov cocktails, and fireworks at police officers Sunday at the construction site.

Several pieces of construction equipment were set on fire, Atlanta’s police Chief Darin Schierbaum said during a midnight press conference. Some 35 people had been detained, and other police agencies stepped in to assist city officers.

No officers were injured during the incident, Schierbaum said. Officers used nonlethal enforcement methods to disperse the crowd and detain those involved, he said.

“This was a very violent attack, very violent attack,” Schierbaum said. “This wasn’t about a public safety training center. This was about anarchy … and we are addressing that quickly.”

The names of those in custody and the criminal charges were not immediately available early Monday, the newspaper said. But Schierbaum said many were not from the Atlanta area.