Chinese authorities in the troubled northwestern Xinjiang Uyghur Autonomous Region have tightened security in its capital, Urumqi, on the second anniversary of deadly ethnic riots in the city.
Officials detained a man and closed down a group of market stalls after their owners refused to take part in a photo opportunity with visiting regional leaders on the eve of a sensitive anniversary, according to an exile Uyghur group.
Xinjiang's Communist Party boss, Zhang Chunxian, visited a night market on Monday, in a show of ethnic unity.
An Urumqi resident surnamed Long said the message was clearly understood.
"Several of the big bazaars were shut down after the July 5 incident," he said. "Now, he is visiting the bazaars, a very clear signal to the outside world that everything is normal."
But overseas Uyghur sources said behind the television footage was a tightening regime of checks and security measures.
"They were carrying out blanket searches in the middle of the night in the part of Urumqi near the racetrack," said Dilxat Raxit, spokesman for the Munich-based World Uyghur Congress, referring to a bazaar frequented by Uyghurs.
"They have been carrying out a 'clean-up' campaign in the outlying districts of the city in recent days," Raxit said, referring to Uyghur neighborhoods.
"Anyone whose identity they can't confirm is told to leave."
Clashes between Uyghur demonstrators and police on July 5, 2009 sparked a three-day rampage of violence between the majority Chinese Han and the Uyghurs, leaving nearly 200 people dead, according to official figures.
The original demonstration had called for further investigation into the deaths of Uyghurs during ethnic riots at a toy factory in the southern province of Guangdong.
The ensuing military crackdown saw dozens of Uyghurs detained, with an unknown number sentenced for attempting to "split the motherland" or for subversion, overseas rights groups said.
Amnesty International said on Tuesday that China has jailed dozens of Uyghurs and executed nine people it blamed for instigating the riots, detained and prosecuted hundreds of others, and ramped up spending on security.
Last month, Kazakhstan extradited a Uyghur schoolteacher who had been granted United Nations refugee status to face charges of terrorism in China, brushing off concerns he could be tortured and that the charges against him were trumped up.
Raxit said the authorities had also imposed restrictions on religious practices at mosques in the city ahead of Tuesday's anniversary.
"They have all gone home," said an employee who answered the phone at a mosque in the city, but declined to say whether the worshipers had been ordered to leave.
"As soon as they were done with their prayers, they all left."
And a Uyghur employee who works in a residential community in the Shanxixiang area of the city said the police were carrying out regular checks on residents.
"Everyone has to sign in in the evenings," she said. "Some of the residents ... we go up and check on in the evening."
But she said such restrictions were common in Urumqi, even before the anniversary. "This is all part of the job of renting out apartments,"
Strong police presence
A Han Chinese resident of Urumqi said police had set up checkpoints in recent days at the bazaar near the racetrack, with local residential officers on patrol.
A second resident surnamed Li said there was a strong armed police presence on the streets of Urumqi, more than last year.
"I think they are afraid that there will be some kind of spontaneous incident," Li said. "There are patrols everywhere, in cars and on foot."
He said the two ethnic groups had shown no overt signs of tension, however.
"Before, no one would go into a Uyghur restaurant, but now things have changed and everyone just gets on with eating and drinking," Li said.
Zhang Mingfu, the relative of one of the Han Chinese who died in the riots, said he and a group of family members had recently visited his dead brother's grave.
He said there were plainclothes police at the cemetery, but that they didn't interfere with their paying respects.
"There were other relatives there sweeping graves as well," Zhang said.
Texas-based travel blogger Josh Summers, who was in Urumqi at the time of the riots, recalled in a post on Tuesday:
"I remember this day just like it was yesterday. I remember the frantic phone calls from friends, the police marching down the empty streets wearing riot gear, and for the first time not a single car, taxi or bus ferrying people from one place to another."
"We all just locked ourselves in our homes and waited for time to pass."
Reported by Hai Nan for RFA's Cantonese service, and by Qiao Long for the Mandarin service. Translated and written in English by Luisetta Mudie.