Police shot and killed a man in a Ferguson street after he twice fired on officers following a report that he had been brandishing a weapon, authorities said.

The St. Louis County Police Department said Monday that detectives are investigating the fatal shooting, which occurred Sunday night. Four county police officers were involved, and they ranged in age from 26 to 40 and in experience from two to 16 years in law enforcement.

Police did not immediately identify the man who died or name the officers involved.

Ferguson was the site of months of protests in 2014 after 18-year-old Michael Brown, who was Black and unarmed, was fatally shot by a city police officer. No charges were filed and Officer Darren Wilson resigned in November 2014.

St. Louis police said Sunday night’s incident resulted in a call to Ferguson police, and an officer was fired upon reaching the site on a residential street. Ferguson police then asked the St. Louis County police for help.

County police began search for the suspect and encountered him two blocks to the south. The man began firing at officers, and they returned fire. The suspect was pronounced dead at the scene.

Officers recovered a handgun at the scene.