Chinese state media say 129 people have been killed and more than 800 hurt in violence in the country's western Xinjiang region.
The official Xinhua News Agency did not immediately give any other details Monday on the number of deaths. It earlier reported that four people had been killed in violence after nearly 1,000 protesters from a Muslim ethnic group rioted Sunday in the region's capital Urumqi, overturning barricades, attacking bystanders and clashing with police.
The protesters were demanding an investigation into a fight between Uighurs and Han Chinese workers at a southern China factory last month that state media said left two people dead.
Activists said police fired shots in the air and used batons to disperse a crowd that had swelled to nearly 1,000.
The late-afternoon protest in the city of Urumqi was a rare mass demonstration in Xinjiang province, a region that has seen occasional separatist violence against Chinese rule.
More than 300 people, mostly members of the largely Muslim Uighur ethnic group, had gathered to demand an investigation into last month's brawl between Uighur and Han Chinese workers at a toy factory, said Gulinisa Maimaiti, a 32-year-old employee of a foreign company who took part in the protest.
Silent protest at first
At first, the 300 people held a silent, sit-down protest at the People's Square in Urumqi, Gulinisa said.
"We are mourning our compatriots who were beaten to death in Guangdong," Gulinisa said in a phone interview.
Accounts of what happened differed, but the violence seemed to have started when the crowd, which Gulinisa said grew to 1,000 people, refused to disperse.
Xinhua News Agency said earlier the crowd attacked passers-by, torched vehicles and interrupted traffic on some roads.
Gulinisa said police pinned protesters to the ground before taking some 40 protesters away.
"The police fired shots into the sky. They took people away in cars," he said.
Dilxat Raxit, a spokesman for the pro-independence World Uighur Congress based in Germany, said he received calls from Urumqi describing the protest as peaceful until police used force to try to clear the square.
"Riot police were using police batons to beat people," he said. One caller he spoke with said police opened fire.
Dilxat said some protesters were beaten badly.
Video shot from a building nearby and photos from mobile phones taken from the protest showed people running from police and a car on fire. In other shots, smoke rises in the distance and fire engines race to the protest.
The Urumqi police and city government refused or declined to comment about the incident.
Tensions between Uighurs and Chinese are never far from the surface in Xinjiang, China's vast Central Asian buffer province.
Uighur separatists have waged a sporadic campaign for independence in recent decades, and the military, armed police and riot squads maintain a visible presence in the region.
After a few years of relative calm, separatist violence picked up last year with attacks against border police and bombings of government buildings.
