Los Angeles police officers have shot and killed a man after he was wrestled to the ground during a confrontation captured on video and viewed by millions online.

Authorities say the man was shot after grabbing for an officer’s gun.

After the shooting, police are seen drawing their batons and warning an angry crowd to step back. Several onlookers shouted at the officers, accusing them of going too far.

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Other recent deaths during police actions in New York and in Ferguson, Missouri, and the lack of prosecution of the officers involved, have brought nationwide protest.

The violence on Sunday also had echoes of August’s Los Angeles police shooting of 25-year-old Ezell Ford, whose death in a struggle with officers brought demonstrations in the city.

Ford was unarmed, but police said he was shot only after reaching for an officer’s gun.

Witnesses to the incident, which happened on Sunday local time, told the Los Angeles Times that the man was known on the street as Africa. But his race was unclear from the video, which showed most of the figures in shadow.

A still from a YouTube video of the shooting.

The witnesses said the man had been there for four or five months amid the tents, sleeping bags and trash of Skid Row, where many of the city’s homeless stay.

Los Angeles Police Department Commander Andrew Smith said three officers, one of whom is a sergeant, shot the man as they struggled on the ground for control of one of the officer’s weapons

The officers had been responding to a report of a robbery, and a stun gun proved ineffective, he said.

Police planned to use the video in their investigation, trying to amplify its sound and pictures to figure out exactly what happened, Smith said.

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

On the video, six officers can be seen responding to the scene. They begin wrestling with the man as he takes swings at them.

Two of the officers break away to subdue and handcuff a woman who had picked up one of their dropped batons.

The struggle becomes increasingly blurry and distant, but shouting can be heard, followed by five apparent gunshots.

Police did not release the man’s name or give any other identifying details, and Smith said he did not know whether the man was homeless.

One witness, Jose Gil told the LA Times he saw the man swinging at police then heard one of them shout, “He’s got my gun!” before the shots were fired.