Police used flash-bang and tear-gas grenades to stop a protest against the construction of a police and firefighter-training center in Atlanta, which opponents have dubbed “Cop City.”

Over 400 people marched from a suburban park in DeKalb County to the protest site, chanting, “Stop Cop City,” and “Viva Tortuguita,” referring to an activist killed by state troopers earlier this year while camping in the forest in protest.

On a road near the training center, a wedge of marchers, some wearing masks, goggles, and chemical suits to protect them from tear gas, tried to push into a line in riot gear of officers. Officers deployed tear gas after pushing back the marchers. One protester hurled a tear gas canister at officers.

Darin Schierbaum, Atlanta Police Chief, said that the protesters had disobeyed the order to stop the marches and noted they did not have a permit. He said that marchers wearing gas masks were a sign they wanted to provoke the police.

This is not a group who has Atlanta’s best interests at heart. Schierbaum stated that a group left Gresham Park today prepared to destroy, to harm and to cause destruction.

Some protesters admitted they intended to enter the site of construction as an act civil disobedience but denied any intention of violence.

Kamau Franklin, Community Movement Builders said: “The police have continued to demonstrate that they are a group who is weaponized towards the public at large. Especially the public that has had the nerve to protest police violence and actions.”

The protests against the proposed center of training have lasted for over two years. Georgia Attorney General Chris Carr, using Georgia’s anti racketeering laws, obtained a broad indictment last August. He charged 61 protesters and referred to them as “militant narchists.”

The protesters called the march on Monday “Block Cop City”, and there were events held all over the country to support this movement in the recent weeks. The latest attempt to stop the construction of a controversial project has galvanized anti-police and environmentalist protesters in the United States.

Some marchers tried to flee the conflict, while others attempted to wash off the tear gas. Dozens ran into the forest near the site where the training centre is being constructed and emerged with their hands raised. The group of marchers eventually returned to their starting point without being arrested. The only visible injuries were vomit and irritation caused by the tear gas.

The site was guarded by police agencies, including DeKalb County Police Department as well as Georgia State Troopers.

Atlanta Mayor Andre Dickens, along with other supporters of the facility, say that the $90 million 85-acre facility will replace insufficient training facilities and assist the police department to recruit and retain officers. Opponents claim the facility will lead to increased police militarization, and its construction in South River Forest in a majority-Black poor area could worsen environmental damage.

Franklin said that the march was a call to civil disobedience. Sam Beard, a protester, said that activists were urged to refrain from bringing weapons, using incendiary device or destroying construction equipment before the march.

Schierbaum, however, displayed at a news conference in the afternoon what appeared to be hand-made tree-planting tools with metal blades and long sticks. He claimed that they were meant as weapons and not garden implements. Schierbaum also showed a gasmask and bolt cutters, and claimed that umbrellas used Monday by “professionals protesters and anarchists”, could be used to shield themselves against tear gas or push through police barriers.

Schierbaum stated that “we see a number devices that appear innocent at first glance but are used in an aggressive and violent way.”

Franklin said that some protesters did plant trees as they retreated after the confrontation.

Some protesters who took part in the march on Monday hoped to reoccupy a wooded area, which includes the adjacent park and the construction site. The activists camped in the woods for months before police forced them to leave in January. This sweep also included the shooting death of 26-year old protester Manuel Esteban Paez Teran (also known as Tortuguita).

Last month, a prosecutor declined to press charges against state troopers that shot Paez Teran. The prosecutor said the activist had shot at a trooper but the use of deadly force by law enforcement was “objectively rational.”

Paez Teran’s parents spoke to the media before the march. They have previously said that they don’t believe the version of events given by authorities and called for an independent inquiry. An autopsy ordered by the family concluded that Paez Teran was shooting with his hands in the air.

Belkis Teran, speaking to The Associated Press, said, “I can see my son in every single one of them.” Manuel always said that to fight the police you must be happy. So we brought happiness.

The project’s opponents have at times been violent and vandalistic. Prosecutors have now characterized the protest movement, as a conspiracy. They say it led to crimes such as possessing fire-accelerators and throwing Molotov cocktail at police officers.

The majority of those charged in August with racketeering had been previously accused of other crimes related to the movement.