MORE than 20 people faced domestic terrorism charges on Monday after dozens wearing black masks protested at the building site for a police training centre outside Atlanta, Georgia, where one protester was killed in January.

The site in a wooded area, dubbed “Cop City” by demonstrators, has become the flashpoint of an ongoing conflict between authorities and activists who have joined forces to protect the environment.

Other protesters appears to be opposing corporations that are alleged to be helping fund the project through donations to a police foundation.

Bottles and stones were thrown at officers during a demonstration on Sunday at the place where 26-year-old environmental activist Manuel Esteban Paez Teran — known as “Tortuguita” — was fatally shot by officers in January during a raid on a protest camp.

Defend the Atlanta Forest, a social media site used by members of the movement, tweeted on Monday that the 23 people arrested were not violent agitators “but peaceful concert-goers who were nowhere near the demonstration”.

Activists oppose the spending of millions of dollars on the $90 million police facility, pointing out that it would be surrounded by poor neighbourhoods in a city with one of the highest degrees of inequality in the United States.

Opponents also say that the training centre would be used to practice “urban warfare” and that, covering 85 acres, it would require the felling of so many trees as to be environmentally damaging.

Rashad Robinson, president of Colour of Change, a civil rights organisation working alongside activists in Atlanta, said: “This just takes up a lot of space in a black community … and it provides more access, more tools and more resources to an institution that actually needs more accountability.”

Many of those already accused of violence in connection with the protests are being charged with domestic terrorism, an offence punishable by up to 35 years in prison.