XINJIANG, in the north-west of China, has been rocked by bloody riots that have left at least 140 people dead, according to Chinese state media.

Protests by ethnic Uygurs in Urumqi city and elsewhere in Xinjiang province turned bloody when confronted by armed police on Sunday night, resulting in the most deadly officially acknowledged mass unrest since the Tiananmen Square massacre in 1989.

Amateur footage on video-sharing websites showed police and fire engines rushing to the scenes accompanied by background sounds of gunshots and explosives.

Authorities said the situation was under control by Monday morning but information is tightly controlled and difficult to verify. Authorities have cut normal channels of electronic communication.

Beijing blamed outsiders for plotting separatist violence against China, echoing its handling of the bloody riots that rocked Tibet last year.

Late yesterday the official Chinese-language media said only "a few" civilians had died but the midday China Central Television news showed vehicles and buildings ablaze, rioters overturning police cars and bloodied and dazed ethnic Han Chinese civilians clustering among the smoke and debris.

Official English language services later increased the death toll from three to 140 and said it was still climbing.

A Xinjiang provincial propaganda official was quoted on Xinhua's English language news service as saying 140 people were dead, 828 injured, at least 260 vehicles attacked or set on fire and 203 houses damaged.

"The situation is very dangerous and I plan to leave for Beijing tomorrow night," a Uygur source in Urumqi told the Herald before the mobile phone line was cut.

Internet services around Urumqi and other big towns were cut yesterday, according to social message services.

The protesters appear to have been mainly Uygur, a Muslim Turkic-speaking ethnic group that once dominated the Xinjiang area until waves of Han Chinese moved there in the past 60 years. Authorities have imposed special limits on Uygurs' travel, religion and education.