Meghan O'Donnell, 29, of St. Louis prays at the spot where 18-year-old Michael Brown was killed Sunday evening in Ferguson, Mo. A few thousand people have crammed the street where the black man was shot by a suburban St. Louis police officer.

FERGUSON, Mo. — A day of anger over a fatal police shooting of an apparently unarmed black man in suburban St. Louis turned to mayhem as people looted businesses, vandalized vehicles and confronted police in riot gear.

Chaos erupted after a candlelight vigil Sunday for 18-year-old Michael Brown, who police said was shot multiple times Saturday after a scuffle involving the officer, Brown and another person in Ferguson, a predominantly black suburb of the city.

County Police Chief Jon Belmar said the shooting occurred after an officer encountered Brown and another man outside an apartment complex in Ferguson.

Belmar said one of the men pushed the officer into his squad car, and a struggle began. Belmar said at least one shot was fired from the officer’s gun inside the police car. Ferguson Police Chief Tom Jackson said authorities were still sorting out what happened inside the police car.

Several businesses near the shooting scene were looted, including a convenience store, a check-cashing store, a boutique and a small grocery store. People took items from a sporting goods store and a cellphone retailer and carted rims away from a tire store.

TV footage showed streams of people walking from a liquor store carrying bottles of alcohol, and in some cases protesters stood atop police cars or taunted officers who stood stoic, some carrying shields and batons. Video posted online by the St. Louis Post-Dispatch showed a convenience store on fire.

Witnesses reported seeing people vandalize police cars and kick in windows. Television footage showed windows busted out of a TV station van.

Police struggled to catch any looters because crimes were happening at several locations in Ferguson and spilling into neighboring communities, Mayor James Knowles said. It wasn’t immediately clear how many arrests were made. Authorities set up blockades to keep people from the most looted areas.

St. Louis County Executive Charlie Dooley said there were no reports of injuries as of about 11 p.m. But there were scattered reports of assaults into the early morning.

“The small group of people are creating a huge mess,” Knowles said. “Contributing to the unrest that is going on is not going to help. ... We’re only hurting ourselves, only hurting our community, hurting our neighbors.”