ATLANTA - A protest broke down into momentary chaos and multiple arrests in downtown Atlanta on Saturday as a group of about 100 demonstrators marched to demonstrate against the police after an environmental activist was killed earlier this week.

The activist, a “forest defender” who goes by the name Tortuguita, was killed Wednesday as authorities disbanded a group of protesters who gathered around the site of a planned public safety training center that the opposition calls “Cop City.”

The Georgia Bureau of Investigation said Tortuguita was killed after shooting a state trooper in the abdomen, causing nonfatal injuries, but others have called for an independent investigation into the killing, according to the Associated Press. The Georgia Bureau of Investigation said that the incident was not recorded on body cameras, the AP reported.

Some of the protesters who marched on Saturday carried banners that read, “You Can’t Kill us All, “Justice for Tortuguita” and “Trees give life, police take it.”

As demonstrators made their way up Peachtree Street, in the heart of Atlanta’s commercial and entertainment district, some in the group, clad in all black, began smashing windows and detonating fireworks, targeting Wells Fargo Bank, Chase Bank and another building that reportedly houses the Atlanta Police Foundation offices.

An Atlanta police car appeared to have been set on fire in front of the city’s Hooters restaurant, which was packed with people watching the Kansas City Chiefs-Jacksonville Jaguars NFL playoff game. Tourists and NFL football fans hurried indoors, as police descended on the scene and tackled several demonstrators.

Six people were arrested and explosive devices were covered, Atlanta’s police chief, Darin Schierbaum, said in a news conference, but no one was injured. He emphasized that those who caused property damage were a small subset of other peaceful demonstrators.

Police are still assessing whether they need to make more arrests over broken windows in at least three businesses, Schierbaum said.

Andre Dickens, the city’s mayor, spoke at the news conference and said that the city “will not tolerate violence or property destruction.”

“My message is simple for those who seek to continue this kind of criminal behavior: We will find you, and we will arrest you and you will be held accountable.”

After demonstrations appeared to have largely scattered, dozens of Georgia State Police officers responded into the city to support Atlanta police. The Atlanta police also shut down about a four-block area of downtown.