A video posted on YouTube shows a fight between a group of skateboarders and art vendors at San Francisco's Justin Herman Plaza.
Artist Jenifer Martinez, who recorded and posted the video, said the brawl reported Friday started when skateboarders brought a disagreement onto the plaza.
"The vendor got in between and said, 'Hey, don't fight in our plaza area.' And that's when they started trashing stuff," Martinez said of the skateboarders.
Martinez said two vendors were treated for injuries at area hospitals and are recovering at home.
The area is popular with tourists and often full of commuters walking to and from the San Francisco Ferry Building.
San Francisco police said they are investigating the incident.
Anyone who recognizes any of the skateboarders in the video are asked to contact the San Francisco Police Department at 415-553-0123.
