LOS ANGELES — Los Angeles Police Chief Charlie Beck said Wednesday he has yet to see evidence that would justify one of his officers fatally shooting an unarmed homeless man near Venice Beach.

Beck cautioned that his department's investigation was just underway but told reporters 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.

Department investigators have not interviewed the officer because he is on medication to treat a knee he hurt during the struggle, Beck said.

The union representing officers criticized the chief's remarks as premature and prejudicial. In a written statement, the Los Angeles Police Protective League called Beck "completely irresponsible" to publicly opine "without having all of the facts."

Tuesday's confrontation began late at night when two officers responded to a 911 call saying the man, believed to be in his 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 walking away but then came back and began struggling with someone on the sidewalk, according to a police news release. The officers tried to detain the man, who was shot during the struggle, police said, and the man died at the hospital. No weapon was recovered at the scene, police spokeswoman Liliana Preciado said.

— The Associated Press