The mayor of Berkeley, a St. Louis suburb, called for calm on Wednesday following violent protests that erupted one day after a suburban St. Louis police officer shot a black 18-year-old who police said pointed a gun at the officer at a gas station.

Scuffles had broken out early Wednesday between police officers and a vocal crowd of several hundred people who taunted the officers at the scene. One officer was injured after he was stuck with a brick and police reported several small explosives being used by protesters. There were four arrests.

Berkeley is just a few miles from Ferguson, where a white police officer fatally shot black 18-year-old Michael Brown in August. The suspect on Wednesday was also 18.

Theodore Hoskins, the mayor of Berkeley, said the surveillance video appears to show that the teen did raise the gun at the police officer. Hoskins, however, said it was a preliminary evaluation and called on a full investigation.

"You couldn't even compare this with Ferguson or the [Eric] Garner case in New York," Hoskins, who is African American, said.

Authorities have not released any information about the identity or ethnicity of the man killed but The St. Louis Dispatch reported that the victim's name as Antonio Martin. obtained surveillance video from the scene.

According to a statement from St. Louis County police spokesman Sgt. Brian Schellman, a Berkeley police officer was conducting a routine business check at a gas station around 11:15 p.m. Tuesday when he approached two men.

The nearly two-minute video clip shows two young men leaving the store at about the time a police car rolls up. The officer gets out and speaks with them. About a minute-and-a-half later, the video appears to show one of the men raising his arm, though what he is holding is difficult to see because they were several feet from the camera. Belmar said it was a 9mm handgun.

The other man ran away, and police are searching for him.

The 34-year-old white police officer, a six-year veteran of the Berkeley Police Department, is on administrative leave pending an investigation, Jon Belmar, the county police chief, said.

"He will carry the weight of this for the rest of his life, certainly for the rest of his career. So there are no winners here."

Toni Martin, who identified the suspect as her son, told the newspaper that he was with his girlfriend at the time of the shooting.

The protesters who gathered early Wednesday milled around the gas pumps at the station, some yelling at police officers. Some wore strands of yellow police-line tape draped around their neck, with others using it as a headband. Authorities from multiple agencies, some in riot gear, stood among the protesters.

Across the street, the glass doors of a convenience store were shattered, one of the doors left hanging from a single hinge. Police stood guard, turning people away.

The crowd dispersed but police officers remained at the scene as dawn approached.

Orlando Brown, 36, of nearby St. Charles was among the protesters. He said he didn't have all the details about the shooting but said he wondered if it was a case of police aggression.

"I understand police officers have a job and have an obligation to go home to their families at the end of the night," he said. "But do you have to treat every situation with lethal force? ... It's not a racial issue, or black or white. It's wrong or right."

Brown said he was pepper-sprayed during the protest as police tried to separate him from a friend whose hand he was holding. He said his friend was arrested for failing to disperse. The shooting sparked a protest of 200 to 300 people, authorities said.

Brown's death led to weeks of protests and some looting in the St. Louis area, actions that were renewed last month when a grand jury chose not to indict Officer Darren Wilson in the killing.

"We had several bricks thrown at officers," Belmar said. There were reports of explosives used and one officer was injured after getting hit by a brick. Four protesters were arrested.

Fox News' Edmund DeMarche and The Associated Press contributed to this report