Hou Hanmin, spokeswoman for the government of the northwestern region, told AFP the attackers were both Uighurs, adding the suspect who was still alive had been detained.

"The case is still under investigation so I don't have more information," she said.

According to tianshannet.com, a website run by the regional government, the two attackers hijacked a truck that was waiting at a light at a night market in Kashgar, an ancient Silk Road city near the border with Kyrgyzstan.

They killed the driver, ploughed the vehicle into passers-by on a nearby pavement, then got off the truck and started stabbing people at random, leaving six bystanders dead before the crowd turned on them and killed one attacker.

Police in Kashgar would not comment when contacted by AFP.

The attack is the latest bout of unrest to hit Xinjiang -- a vast, arid but resource-rich region bordering Central Asia, home to more than eight million Turkic-speaking Uighurs -- that has long been plagued by unrest.

Earlier this month, more than 20 people were killed in a violent clash with police in the remote city of Hotan.

State media quoted an official in Xinjiang as saying that clash was a "terrorist" attack, adding that four people including a police officer were killed when a crowd set upon a police station.

But Uighur activists called it an outburst of anger by ordinary Uighurs and said security forces beat 14 people to death and shot dead six others during the unrest.

Many Uighurs are unhappy with what they say has been decades of repressive rule by Beijing and the unwanted immigration of China's dominant Han ethnic group.

While standards of living have improved, Uighurs complain that most of the gains go to the Han.

This culminated with savage Uighur attacks on Han Chinese in the regional capital Urumqi in July 2009.

The government says nearly 200 people were killed and 1,700 injured in the riots -- China's worst ethnic violence in decades -- which shattered the authoritarian Communist Party's claims of harmony and unity among the country's dozens of ethnic groups.

China threw a huge security clampdown onto Xinjiang after the violence, and many Uighurs are enraged by the arrests or alleged disappearances of people rounded up across the region in the aftermath.