Three Los Angeles police officers shot and killed a man on the city's Skid Row during a struggle over one of the officers' guns, authorities said late Sunday. 

The shooting, which took place shortly after noon Sunday, garnered widespread attention after video captured by a bystander was posted on Facebook. The video shows four officers struggling with the man near a curb when the clicking of what sounds like a stun gun is heard and then about five shots ring out.

Someone is heard yelling, "Drop the gun,'' right before the shots are heard. Onlookers then accost the officers at the scene. The video was apparently posted online within hours of the death by a man named Anthony Blackburn.

LAPD Cmdr. Andrew Smith said the officers, one of whom is a sergeant, were responding to a report of a robbery and used lethal force after a stun gun proved ineffective. He added that the department was aware of the video, and and would attempt to amplify its sound and pictures to figure out exactly what happened.

"The video is disturbing," Smith said at a briefing with reporters late Sunday night. "It's disturbing any time anyone loses their life. It's a tragedy."

Smith also said at least one of the officers was also wearing a body camera.

The Los Angeles Times reported that witnesses identified the man by his street name, "Africa." One witness said the man had been fighting with someone else in his tent when police arrived. That witness said officers dragged the victim out of the tent before he began fighting. Other witnesses said the man punched and kicked the officers before reaching for their service weapons. 

"He didn't have no weapon, they just shot him," a witness, Yolanda Young, told KTTV. "They could have just wrestled him down and took him to jail, but they shot him five times. "

"When they couldn't apprehend him, that's when they backed up and just started shooting. Pow, pow, pow, pow. There was five of them. They could have apprehended him," added another witness, Ceola Waddell.

A woman who lives in an apartment nearby told the Times that the victim had lived on Skid Row for between four and five months after being released from a mental health facility. Another local resident told the paper that police had repeatedly come by to ask "Africa" to take down his tent during the daylight hours, as required by a court agreement. Smith did not confirm any information about the victim, including his real name, his living situation, or the status of his mental health.

Earl Ofari Hutchinson, head of the activist group the Los Angeles Urban Policy Roundtable, called on the Police Commission to hold a special hearing on use of force by officers in Skid Row encounters.

Hutchinson said in a statement that the shooting "underscores the need for the police commission to hold a special hearing to fully examine police tactics and training in the use of deadly force by LAPD officers involving skid row residents many of whom have major mental challenges."

Tents and cardboard shelters cover the sidewalks of Skid Row, the downtown neighborhood where an estimated 1,700 homeless people live. Many of them struggle with mental illness and addiction.

The shooting was under investigation by the Los Angeles Police Department, its independent inspector general, and the Los Angeles County District Attorney's Office.

The Associated Press contributed to this report.

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