Aug. 19, 2015: St. Louis police gather at the scene of a fatal officer-involved shooting at Walton Avenue and Page Boulevard in St. Louis. An armed man fleeing from officers serving a search warrant at a home in a crime-troubled section of north St. Louis was shot and killed Wednesday by police after he pointed a gun at them, the police chief said. (David Carson/St. Louis Post-Dispatch via AP)

Nine people were arrested and St. Louis police used tear gas to clear a street of protesters after an armed man fleeing from officers serving a search warrant was shot and killed Wednesday.

Approximately 150 people gathered at the scene of the shooting late Wednesday, many of them hurling obscene gestures and expletives at investigators and questioning the police use of deadly force. St. Louis Police Chief Sam Dotson said tear gas was used after protesters threw glass bottles and rocks at police. Some chanted "Black Lives Matter," a mantra used a year ago after the police shooting death of 18-year-old Michael Brown in nearby Ferguson. 

The St. Louis Post-Dispatch reported that a vacant home had been set on fire near the scene. Dotson also said that officers were responding to reports of burglaries in the area.

At a press conference earlier in the day, Dotson said two suspects fled from the home about noon Wednesday on the city's north side before the 18-year-old turned and pointed a handgun at the officers, who shot him. That suspect, identified later in a statement by police as Mansur Ball-Bey of St. Louis, died at the scene. Police are searching for the second suspect, who they said is believed to be in his mid- to late teens.

Both officers, who are white, were unharmed, according to a police report.

Dotson said four guns, including the handgun wielded by the dead suspect, and crack cocaine were recovered at or near the home, which last year yielded illegal guns during a police search.

A man and woman who were also inside the home were arrested, Dotson said.

Police obtained the search warrant because they believed the home harbored suspects in other crimes, Dotson said.

Dotson didn't specify which crimes, but he noted that a killing happened on the same street Monday and a nearby market just was riddled by bullets.

That area also is near where a 93-year-old veteran who was part of the Tuskegee Airmen -- black World War II pilots -- was the victim of crimes twice within a few minutes Sunday, being robbed and then having his car stolen. The veteran was unhurt, and his car was found Tuesday blocks from where it was taken.

Many of those who gathered Wednesday afternoon voiced anger at police. As police removed their yellow tape that cordoned off the scene, dozens of people converged on the home's front yard, many chanting insults and gesturing obscenely at officers. Several onlookers surrounded individual officers, yelling at them.

"Another youth down by the hands of police," Dex Dockett, 42, who lives nearby, told a reporter. "What could have been done different to de-escalate rather than escalate? They (police) come in with an us-against-them mentality. You've got to have the right kind of cops to engage in these types of neighborhoods."

Another neighborhood resident, Fred Price, said he was skeptical about Dotson's account that the suspect pointed a gun at officers before being mortally wounded.

"They provoked the situation," Price, 33, said. "Situations like this make us want to keep the police out of the neighborhood. They're shooting first, then asking questions."

Dotson said police would release video showing that officers gave multiple orders to clear the street and warnings that the tear gas would be used.

Tensions remain high in the St. Louis area after unrest during the anniversary of Brown's death. Brown, who was black and unarmed, was fatally shot by Ferguson officer Darren Wilson on Aug. 9, 2014. A St. Louis County grand jury and the U.S. Justice Department declined to charge Wilson, who resigned in November.

The Associated Press contributed to this report.