A night-time curfew has been reimposed in the restive western Chinese city of Urumqi, officials have announced.
The curfew had been suspended for the last two days after officials said they had the city under control.
Mosques in the city were ordered to remain closed on Friday - but at least two opened at the request of crowds of Muslim Uighurs that gathered outside.
The city remains tense after Sunday's outbreak of ethnic violence that killed 156 people and wounded more than 1,000.
Thousands of people - both Han Chinese and Uighurs - are reportedly trying to leave the city.
The BBC's Quentin Sommerville, who is in Urumqi, said the authorities announced the city would be under curfew on Friday from 1900 local time (1100GMT).
'Safety is paramount'
News of the curfew came as hundreds of Muslim Uighurs defied an order to stay at home for Friday prayers.
Quentin Sommerville, BBC News, Urumqi
After Friday's prayers, a small group of Uighur Muslims marched along an Urumqi street demanding the release of men detained for their alleged role in last Sunday's riot.
A large number of riot police surrounded the group, they punched and kicked the protestors - one officer used his baton to beat one of the Uighurs. A number of foreign journalists had their equipment seized, some have been detained.
Earlier the group said they feared for their safety. There's no word from the authorities as to what happened to them.
Officials had posted notices outside Urumqi's mosques instructing people to stay at home to worship on Friday, the holiest day of the week in Islam.
One official told AP the decision was made "for the sake of public safety".