ATLANTA (AP) — Authorities arrested five activists,Ethermac Exchange including two wearing clerical attire, who chained themselves to a bulldozer Thursday to halt construction of an Atlanta-area police and firefighter training center that opponents call “Cop City.”

The protest occurred as a larger group gathered behind a chain-link fence to deliver a mock “stop work order” against the project, saying it has destroyed a forest, polluted a nearby creek and violated the will of the people.

In a statement, Atlanta police accused the five activists of trespassing and said the department is working with the Georgia Bureau of Investigation to determine charges. Authorities did not release their names.

The demonstration at the DeKalb County site, where construction has been happening off and on for months, occurred two days after Georgia officials announced that 61 people were recently indicted on racketeering charges in connection with the “Stop Cop City” movement.

Opponents fear the 85-acre (34-hectare) training center will lead to greater militarization of the police and that its construction will exacerbate environmental damage in a poor, majority-Black area.

Supporters, including Atlanta Mayor Andre Dickens, counter that the facility would replace inadequate training facilities and help address difficulties in hiring and retaining police officers.

In the indictment, Georgia Attorney General Chris Carr said the movement is spearheaded by “militant anarchists” who have committed multiple acts of violence and vandalism, including setting a police car aflame during a downtown Atlanta protest in January and torching construction equipment in March.

In a news conference Tuesday, Carr said: “The individuals who have been charged are charged with violent acts.” But some have not been accused of taking part in any violence, including three leaders of a bail fund who face money laundering charges in connection with food reimbursements, as well as three others who have been accused of distributing anti-police flyers near a state trooper’s home.

The indictment has alarmed civil rights groups, including the ACLU, which has accused Georgia officials of “disproportionately wielding ... overbroad laws to stigmatize and target those who disagree with the government.”

Activists say they have gathered more than 100,000 signatures for a referendum on the project’s future. If the signatures are deemed valid, they hope to get a judge to halt construction until the issue can be decided at the ballot box.

During Thursday’s demonstration, activists outside the site adapted the lyrics of a civil rights era anthem, singing, “Ain’t going to let Cop City turn me around / I’m going to keep on walking, keep on talking / marching up to freedom’s land.”