After a night of protests Wednesday sparked by the killing of an 18-year-old black man by a white officer the same day, activists criticized the St. Louis police for “aggressive” tactics that they said recalled the last year’s protests after Ferguson.

Wednesday's shooting came on the first anniversary of the police shooting of another black man in St. Louis, Kajieme Powell. Protesters were already in the area for a march protesting his shooting.

”Tonight was supposed to be peaceful. We were supposed to be remembering #KajiemePowell. Not watching the city burn,” Hands Up United, a racial justice organization, posted on social media.

At least nine people were arrested in the St. Louis demonstration, with protesters saying police began firing smoke and tear gas without warning, local news reported.

St. Louis Police Chief Sam Dotson, in a news conference Wednesday evening, said police gave repeated warnings by bullhorns before firing smoke and tear gas at the protesters.

Dotson said bricks, water bottles and other objects were being hurled at police. At least one car was set on fire, and furniture and other items were being burned in piles on the street.

Kayla Reed, an activist with the Organization for Black Struggle, told the St. Louis Post Dispatch said the police were too aggressive towards a crowd that “never was all that big.”

The Rev. Renita Lamkin of St. Charles, who has regularly attended protests in Ferguson since last year’s killing of black teenager Michael Brown by a white police officer, also said police were too aggressive on Wednesday night. She had attended the protest with several other clergy members, the St. Louis Post Dispatch added.

“There has to be a better way, but the better way is not to terrorize an already terrorized community,” Lamkin told the St. Louis Post Dispatch. “How they deal with the situation is classist and dehumanizing. The people here don’t matter as much to them.”

Law enforcement in Ferguson, as well as other locations like Baltimore, have been criticized over the past year for the aggressiveness of responses to protests over racial injustice and police killings.

St. Louis police said they fatally shot the black teenager, Mansur Ball-Bey, 18, on Wednesday after he allegedly pointed a gun at them. Officers were serving a search warrant when Bey and at least one other young man ran out the back door of the house.

Officers said they ordered Ball-Bey and another man to stop in an alley behind the house when one suspect pointed a gun at officers who then fired four times, killing him, Dotson said.

“Detectives were looking for guns, looking for violent felons, looking for people that have been committing crimes in the neighborhood,” he said.

Racial justice organizations criticized the killing, and posted photos of Ball-Bey on social media in a graduation cap and gown, as well as in photos with friends.

“A young man was killed by STL Police today and now the cops are responding to community turnout w/ gas and arrests,” Ferguson Action, a rights group formed after Brown's death, posted on Twitter.

In nearby Ferguson, a group of about 80 protesters reportedly burned an American flag in Ferguson while chanting an anti-police slogan, the Post Dispatch reported.

Also in Ferguson, local news reported Wednesday that a 9-year-old girl was fatally shot after someone fired shots into her home late Tuesday night, police and the girl's family told The St. Louis Post-Dispatch.

Jamyla Bolden’s grandmother told the paper she ran into the bedroom after hearing the shots around 9:30 p.m. The girl’s mother was shot in the leg.

Ferguson police chief Andre Anderson said authorities would do “everything possible to find the person responsible,” the Post-Dispatch reported.