Berkeley, Mo. police shot and killed a reportedly armed 18-year-old while performing "a routine business check" at a Mobil gas station just miles away from where Michael Brown was killed by Darren Wilson in Ferguson. The teen was with a friend when he allegedly pointed a gun at the officer late Tuesday night.

The identity of the victim has not yet been released by police, but local media have quoted Toni Martin, who claims that her son Antonio was the teenager killed by the officer. She told KSDK that her son did not own a gun, and that he had just left their home to see his girlfriend.

"The Berkeley police officer exited his vehicle and approached the subjects when one of the men pulled a handgun and pointed it at the officer," St. Louis County police said in a statement. "Fearing for his life, the Berkeley officer fired several shots, striking the subject, fatally wounding him. The second subject fled the scene."

Local reports put around 100 people gathered at the gas station in the hours after the shooting, the teen's body lying in the parking lot for "at least" two hours. Some reportedly stood near the police scene overnight. From the St. Louis Dispatch:

The crowd at the station included ministers and some of the people who have been active in the protests related to the fatal shooting of Michael Brown, 18, by a Ferguson police officer in August.

At one point, as some of the protesters grew rowdy, explosive flashes were set off. It was unclear by who.

Also, a QuikTrip store near the Mobil station was damaged by vandals before police officers closed access to it.

Video from the scene depicts at least a dozen police officers engaging the crowd, with the explosive described by the St. Louis Dispatch flashing. From KSDK:

Crowds began assembling at the gas station shortly after the shooting. NewsChannel 5 reporter John Henry said the crowds were relatively calm until sometime after 2 a.m., when some individuals began throwing rocks and bricks in the direction of police. A smoke device was also hurled toward police.

The following video has no audio:

Update: In a press conference this morning, St. Louis County Police Chief Jon Belmar told reporters the teen aimed a 9 mm handgun at the officer, who fired at the suspect three times, hitting him once. Four people were arrested by police last night for assaulting officers; one officer is in the ER after sustaining injuries trying to avoid an explosive. According to police, the officer's body camera was not being worn and his dash cam was not activated.

Police also released security camera footage that "shows the suspect pointing a gun at the officer," though it is difficult to ascertain what exactly is happening.

Update 2: If you jump to about 1:45 in the video and look in the top left corner, you see a man extending his arm toward an officer, but it's still hard to tell if what he is pointing is a gun.

[Screengrab via NBC News]