Authorities in China's troubled northwestern region of Xinjiang have boosted security as ethnic minority Uyghur Muslims celebrated a key festival of their calendar, Eid al-Adha.
Police in the region's western Kashgar city have already detained six Uyghurs outside a mosque for distributing "illegal religious CDs" to people arriving for Friday prayers last week, an exiled Uyghur group said.
The Eid al-Adha is considered a festival of "sacrifice" among Muslims with celebrations peaking on Wednesday.
Dilxat Raxit, spokesman for the Munich-based World Uyghur Congress, said those detained ahead of the festival included a 17-year-old Uyghur girl.
"The government has stepped up its surveillance of mosques," Raxit said. "There are a lot of plainclothes police officers around [the mosques] now."
"The plainclothes police are also going into the mosques, requiring them to comply with government directives on social stability," he added.
A police officer who answered the phone at the Kashgar municipal police department said he was unaware of the detentions in the city.
However, an officer at the Yecheng county police station did not deny the detentions had taken place. "This is an internal matter for the police," the officer said. "I can't answer your questions."
An employee who answered the phone at a hotel in Kashgar said there would be traffic restrictions around the city's main mosque during early prayers.
"Our mosques will be very busy on the day," she said. "There will probably be 500 or 600 people at prayer, perhaps even 1,000. It's like that every year."
She said tourists would be barred from entering the mosques during the festival prayers.
"When Eid is over at the 12th hour, then we will have some activities, like dancing," she added.
Police were carrying out round-the-clock patrols on the streets of Urumqi, the regional capital which was rocked by deadly ethnic violence in July 2009, leaving nearly 200 dead, according to official reports.
An Urumqi resident surnamed Wu said there were armed security patrols all over the city.
"Things are pretty tense on the streets," Wu said. "The special forces are armed to the teeth, and patrolling in groups of three."
"The volunteer security guards, who aren't so combat-ready, are also patrolling in bigger groups of seven, eight, nine, 10," he added.
A non-Uyghur Hui Muslim who answered the phone at a mosque in the city's Tianshan district said that the mosques were expecting several hundred worshipers to attend prayers for Eid al-Adha, at which sheep and goats are sacrificed to recall the sparing of Abraham’s son Ismail.
"Recently, there have been a lot of plainclothes police carrying out surveillance outside the mosques," he said.
"There's no problem here now. The July 7 [violence] is over now," he said, adding that the government had "sorted them out."
"It's only the Uyghurs who are under strict controls," he added.
Meanwhile, government agencies at all levels had recently received orders banning any Muslim members of the ruling Communist Party or government officials from attending Eid prayers in the region's mosques, Raxit said.
"I don't think the Chinese government is sincere about improving the situation of Uyghurs," he added.
China is home to around 23 million Muslims, including the Turkic-speaking Uyghurs and the Hui, whose mother tongue is Chinese, and who have Chinese names.
Around 13,000 Chinese Muslims flew to the annual pilgrimage in Mecca last month, boarding chartered flights from Gansu, Beijing, Urumqi, Yinchuan and Kunming, official media reported.
However, since the Urumqi violence of July 2009, Uyghurs and travel industry sources have said that Uyghurs have been effectively barred from foreign travel if they don't already have a passport, as their applications are being uniformly turned down.
Reported by Hai Nan for RFA's Cantonese service, and by Qiao Long for RFA's Mandarin service. Translated and written in English by Luisetta Mudie.