Riot in Urumqi: The disturbances come after a year of rising tensions between the dominant Han Chinese authorities and the Uighur ethnic minority.
The clashes in Urumqi on Sunday night between police and a 3,000-strong crowd from the Uighur Muslim ethnic minority left burned-out cars and buses and several smashed shop-fronts.
Authorities said all traffic was cleared from the streets on Monday morning to retain order. Another witness said the city of 2.3 million, which is 2,000 miles west of Beijing, was now effectively "on lockdown".
The disturbances come after a year of rising tensions between the dominant Han Chinese authorities and the Uighur ethnic minority - the historical majority in Xinjiang - who say they have been socially and economically marginalised by Beijing's development policies.
Witnesses said the riot began when Chinese police tried to disperse a sit-in protest calling for an investigation into the deaths of two Uighurs during a fight between Uighur and Han workers at a toy factory in Guangdong province, Southern China last month.
The riot and its suppression has echoes of clashes last March in the neighbouring province of Tibet where there are similar simmering ethnic tensions between the historic Buddhist population and Han Chinese who have migrated to the region in recent decades.
The number of dead in Sunday's riot remains unclear. The government's official Xinhua News Agency said that at least three ethnic Han Chinese were killed in the violence, but later added that "unknown number" of people were killed, including a policeman.
