A second night of protests took place in Berkeley, Missouri, after a police officer shot and killed an armed teen.

ST. LOUIS COUNTY — Protesters took to the streets of Berkeley, Mo., for a second night on Wednesday after a white police officer killed a black teenager who police said pointed a gun at him.

Dozens of protesters marched on Interstate 170, shutting it down for a brief time before heading to the Mobil gas station where 18-year-old Antonio Martin was shot and killed Tuesday night.

The shooting happened about 5 miles from Ferguson, where a white police officer fatally shot unarmed Michael Brown in August, sparking months of civil unrest.

NewsChannel 5 crews saw some people trying to get into a store front near the gas station during the protests. Other protesters tried to stop the group. The crews said they heard gunshots during the confrontation.

Berkeley Police Chief Frank McCall told KMOV-TV that six to eight people were arrested.

As the situation escalated, protesters surrounded NewsChannel 5 crews and told them to leave the scene. The crews left when they felt threatened.

About 75 people later staged a peaceful protest early Christmas morning outside a nearby church, according to the St. Louis Post-Dispatch. Police in riot gear were present.

Surveillance video shows the moments before a police officer in Berkeley, Missouri, shot and killed an armed teenager.

St. Louis County Police Chief Jon Belmar said Martin was armed with a loaded handgun, which he pointed at the officer before he was shot. The incident was captured by surveillance cameras.

A night before, a crowd of about 300 people gathered at the gas station, throwing rocks and bricks in a scene reminiscent of the sometimes-violent protests that followed Brown’s death.

Unlike in the death of Brown, who was unarmed and whose shooting was not captured on video, Berkeley Mayor Theodore Hoskins said Wednesday that surveillance footage appeared to show Martin pulling a gun on the unidentified 34-year-old officer, who was questioning him and another man about a theft at a convenience store.

Hoskins urged calm, saying, “You couldn’t even compare this with Ferguson or the Garner case in New York,” referring to the chokehold death of Eric Garner, another unarmed black man killed by a white police officer.

Hoskins, who is black, also noted that unlike in Ferguson — where a mostly white police force serves a mostly black community — more than half of the officers in his city of 9,000 are black, including top command staff.

The mayor of Berkeley, Missouri said the officer-involved shooting that left an armed teen dead Tuesday night is different from what happened in nearby Ferguson in August for several reasons.

State Sen. Maria Chappelle-Nadal, a Democrat who has been critical of how police handled the Brown case, also said the Martin shooting was very different than Brown’s, noting that Martin pointed a weapon at the officer.

“That officer not only has an obligation to protect the community, but he also has a responsibility to protect himself,” said the senator, who is African-American. “Because of the video, it is more than apparent that his life was in jeopardy.”

But Taurean Russell, co-founder of Hands Up United, asked if police had any reason to question Martin in the first place. Mistrust of police remains high among blacks, many of whom are weary of harassment, said Russell, who is black.

St. Louis County Police Chief Jon Belmar did not provide further details Wednesday on the theft about which Martin was being questioned. He said Martin pulled a loaded 9mm handgun and the officer fired three shots while stumbling backward. One hit Martin, who didn’t fire his own gun. He died at the scene.

“I don’t know why the guy didn’t get a shot off, whether his gun jammed or he couldn’t get the safety off,” said attorney Brian Millikan, who is representing the officer. He said that the officer was lucky to be alive and had no choice but to use lethal force.

St. Louis County police and the city of Berkeley are investigating the shooting of Martin, which Belmar called a tragedy for both Martin’s family and the officer, who has been on the force for six years.

“He will carry the weight of this for the rest of his life, certainly for the rest of his career,” Belmar said of the officer. “There are no winners here.”

The officer wasn’t wearing a body camera that had been issued to him, and his cruiser’s dashboard camera was not activated because the car’s emergency lights were not on, Belmar said.

Police were searching Wednesday for another man who was with Martin, who ran away after the shooting.

Belmar said Martin had a criminal record that included three assault charges, plus accusations of armed robbery, armed criminal action and unlawful use of a weapon.

Martin’s was the third fatal shooting of a young black man by a white police officer in the St. Louis area since Brown was killed by Ferguson officer Darren Wilson on Aug. 9. Kajieme Powell, 25, was killed on Aug. 19 after approaching St. Louis officers with a knife and Vonderrit Myers, 18, was fatally shot on Oct. 8 after allegedly shooting at a St. Louis officer.

Each killing has led to protests, as did a grand jury’s decision last month not to charge Wilson in Brown’s death.

In another incident on Wednesday, a person was killed and three others injured in a shooting in downtown St. Louis.

St. Louis police spokeswoman Schron Jackson said officers were called to a shooting around 5:30 p.m. and found four people had been shot. She said one person was pronounced dead at the scene.

St. Louis Fire Capt. Garon Mosby said the three injured people were taken to a hospital and were in a critical condition Wednesday night.

Contributing: Associated Press