Protesters massed in the capital of China's far western region of Xinjiang on Thursday demanding the ousting of its top official, who faced the crowd amid a scare over syringe stabbings that has reignited ethnic tensions, Reuters reported.
The demonstration was a rare public challenge by Han Chinese to the ruling Communist Party in tense Xinjiang, where deadly ethnic strife with Muslim Uighurs broke out in early July.
It also erupted at a sensitive time for China, preparing for the 60th anniversary of the founding of the People's Republic on Oct. 1 with a nationwide security clampdown.
"Resign Wang Lequan, the government is useless!" protesters shouted outside the regional government building in Urumqi, referring to Xinjiang's Communist Party chief, who has held office for 14 years. Others called for his execution.
"Wang Lequan apologise to the Xinjiang people," they yelled, some of them lobbing bottles and other objects in Wang's direction, a witness there told Reuters. He requested anonymity.
He estimated that by early afternoon 3,000 people gathered at the People's Square in central Urumqi. By evening, the streets were empty, he said.
A photograph showed Wang, a round, balding figure, using a microphone to address the crowd from a balcony. The witness said Wang told the crowd that 30 people had been detained over the claimed syringe stabbings.
Other pictures showed people, apparently predominantly Han Chinese, marching through streets, some waving Chinese national flags, as riot police with shields and batons blocked streets.
The official Xinhua news agency said more than 1,000 people were involved in the main protest, which it said began in the morning after claims that a man stabbed a five-year-old girl.
Some witnesses said they saw Uighurs, a Turkic-speaking Muslim people native to the region, being beaten by Han Chinese.
A resident said he had seen a group of Han Chinese protesters beating a Uighur suspected of carrying out attacks with syringes, but he was rescued by police and taken to hospital.
The Xinjiang health office said that over the past two weeks 476 people have gone to hospitals to report apparent syringe stabbings -- 433 of them Han Chinese -- and doctors have "found clear syringe marks in 89 cases," regional television reported.
But Nicholas Bequelin, a China researcher for Human Rights Watch, a New York-based advocacy group, said it was still unclear how much truth or rumour lay behind the claims of stabbings.
"These kinds of rumours do happen in China after unrest," said Bequelin, who closely follows developments in Xinjiang.
"There's always bizarre rumours that spread after violence."
Calls to the Xinjiang government and police went unanswered.
Chinese Foreign Ministry Spokeswoman Jiang Yu told reporters in Beijing said she had no knowledge of any new riot.
"But I can tell you that the Chinese government has the ability to maintain social stability," she said.