ATLANTA (AP) — Atlanta’s police chief on Tuesday urged the public to come forward with information about those who set police motorcycles on fire last month in protest over the planned construction of a public safety training center that critics call “Cop City.”

Police Chief Darin Schierbaum said the vandals have been using “violence, intimidation and fear” to stop the facility’s construction, attacking police vehicles as well as contractors’ construction equipment. Authorities held a news conference to release surveillance photos of “persons of interest” and to announce that the reward for information leading to the culprits’ arrests has been increased from $15,000 to $60,000.

Schierbaum said more than 40 police vehicles were targeted at Atlanta police’s current training center in south Atlanta early July 1. Ultimately, eight motorcycles were set alight and a police officer intervened before more damage could occur, Schierbaum said.

“Had (all) these vehicles been set on fire, the entire precinct would have been ignited,” the police chief said.

About an hour before that attack, vandals had smashed the windows of police vehicles at another location. Authorities believe the group wanted to set those vehicles on fire as well but were spotted by a bystander.

Mayor Andre Dickens and others say the planned $90 million training center would replace outdated training facilities and help address difficulties in hiring and retaining police officers that worsened after 2020’s nationwide protests against police brutality and racial injustice.

Opponents say they worry the facility will lead to greater militarization of the police and that its construction will exacerbate environmental damage in a poor, majority-Black area. Activists have been working to collect more than 70,000 signatures to force a referendum on building the project.

“For those that have legitimate concerns about the construction of a training center, how tax dollars are used, green space usage, we will continue as a department to protect those First Amendment rights,” Schierbaum said.

He added: “This is not about the protection of the First Amendment. This is intimidation, this is fear, this is destruction, and this is targeting key assets that protect this city.”

The Vote to Stop Cop City Coalition issued a statement after the news conference, decrying the lack of “accountability” for the January “murder” of 26-year-old protester Manuel Esteban Paez Terán, known as Tortuguita. The Georgia Bureau of Investigation has said state troopers fired in self-defense after Paez Terán shot at them while they cleared protesters from a wooded area near the site of the proposed facility. But the troopers involved weren’t wearing body cameras, and activists have questioned the official narrative.

“While Atlanta elites focus on limited property damage, tens of thousands of Atlantans are focused on actual violence by the state and have demanded the right to reject this deeply unpopular waste of public funds,” the statement read.