Los Angeles Police Chief Charlie Beck said Wednesday that he has not yet seen evidence to justify one of his officers shooting and killing an unarmed homeless man near Venice Beach.

Beck said that the department’s investigation was just underway but mentioned to reporters that he was “very concerned” by the shooting that occurred Tuesday night as an officer struggled with the man on a block lined with bars and restaurants.

"Any time an unarmed person is shot by a Los Angeles police officer, it takes extraordinary circumstances to justify that, and I have not seen those extraordinary circumstances at this point," Beck said.

The officer in question has not been interviewed by department investigators because he is on medication to treat a knee injury he aggravated during the scuffle, Beck said.

The union representing officers criticized the chief's remarks as premature and prejudicial.

In a written statement, the president of the Los Angeles Police Protective League called Beck "completely irresponsible" to publicly opine "without having all of the facts." President Craig Lally said that by speaking out, Beck "essentially renders the investigation process void."

Tuesday’s confrontation began when two officers responded to a 911 call saying the man, believed to be in his late 20s, had been arguing with a bouncer who would not let him into a bar and was hassling passersby, police said.

The officers spoke to the man, who began to walk away, but then came back and began struggling with someone on the sidewalk, according to a police news release.

Police said the officers tried to detain the man, who was shot during the struggle. The man died at a hospital. No weapon was recovered at the scene, police spokeswoman Liliana Preciado said.

On Wednesday, a small crowd of people shouted at police at the scene. Beck later noted that the officer and the homeless man were black. He said the department will hold a meeting in the neighborhood Thursday.

The department was criticized after an officer fatally shot a homeless man in March on Skid Row, near downtown.

The officers in Tuesday's shooting were not wearing body cameras, but police have surveillance footage from nearby stores that shows the events.

Neither police nor the coroner's office had confirmed the dead man's identity, though Preciado said a 911 caller and several witnesses identified him as one of the area's many transients.

The Associated Press contributed to this report.