Police say a bystander has been shot at a gay pride event in San Francisco when an argument between several young men turned violent.
Officer Carlos Manfredi says several people were detained for questioning after the shooting Saturday evening.
The shooting triggered a chaotic scene as dozens of people ran screaming as officers carrying handguns rushed to the scene.
Manfredi says a 64-year-old man who was caught in the crossfire got shot in the arm. He's hospitalised in stable condition.
Four shots were heard in a witness video posted online.
Manfredi says the argument had nothing to do with the gay pride event.
A concert that was part of the weekend-long gay pride celebration across the city was ending around the time of the shooting.