ROUGH CUT (NO REPORTER NARRATION)
STORY: A violent brawl broke out in central Beijing on Sunday (May 12) between people witnesses said were ethnic Tibetan street vendors and Han restaurant workers.
In footage filmed by dissident artist Ai Weiwei, police tried to control men clashing and hurling chairs in front of a restaurant on the capital's popular 'Ghost Street'.
Once the fight had been mostly dispersed, officers struggled to prevent one group, who onlookers said were Tibetan, from hurling bricks, stones and chairs at the restaurant front.
Ai, China's most famous contemporary artist who has frequent run-ins with China's authorities, said he was out with his mother when he saw the brawl happening at around 5.30pm local time (0930 GMT).
Han Chinese witnesses told Reuters on Monday (May 13) that the fight had started when security workers refused to allow the vendors to sell on the pavement in front of their restaurant.
Restaurant workers refused to speak to Reuters, and it was not immediately possible to confirm the identities of anyone involved in the incident.
It was also unclear whether any brawlers were arrested or seriously injured.
Tibetans, who hail from the vast Himalayan plateau, often chafe under Chinese rule, and sporadic violence with Han Chinese migrants has rocked Tibetan regions in recent years.
Bloody brawl breaks out in Beijing (0:38)
May 13 - Footage filmed by dissident artist Ai Weiwei shows a bloody clash in Beijing. Rough Cut (no reporter narration). ( Transcript )