Chinese dissidents and organisations of Uighur exiles say Chinese security troops opened fire on thousands of demonstrators in the Xinjiang region in northwest China on Monday. They say that 156 Uighurs were killed, almost 900 injured and hundreds arrested.

Authorities in the region have now imposed a curfew in an attempt to curb the disturbances. They have also brought telephone and internet communications in the capital Urumqi to a standstill. Despite these measures, the unrest appears to have overflowed into other cities. Chinese state television has reported that in Kashgar, 1000 kilometres south of Urumqi, hundreds of people wanted to hold a demonstration in front of a mosque.

The latest unrest, which many observers regard as the biggest outbreak of violence in China in the past few decades, erupted after two Uighur workers were killed last week. The Uighurs died in a fight with Chinese workers in a factory in the Guandong province in southern China.

Chinese authorities have made no mention of the cause of death of the demonstrators. However, state television has shown pictures of demonstrators setting police cars on fire. Beijing says the disturbances have been caused by foreign Uighur exiles.

In recent years Islamic Uighurs, who have lived for many years in Xinjiang, have rebelled against the Chinese government and what they say is cultural and religious oppression by the communist party.

Picure of riots from Chinese television