It was the second such incident in the same region this month. Sixteen people, including two police officers, died in a similar clash during an attack near Kashgar town, China's official media reported.
As in the previous incident, the reports on Monday's clashes did not identify the ethnicity of the victims.
The latest fighting came during what was described as a terrorist attack in Yarkand County, close to the old Silk Road city of Kashgar, the China Daily reported, quoting the Xinjiang-Uighur government's official news website www.ts.cn.
"At around 6:30 am, nine thugs carrying knives attacked a police station in Kashgar's Yarkand county, throwing explosive devices and setting police cars on fire," the brief report said. "The police took decisive measures, shooting dead eight and capturing one."
Other details were not immediately available .
The Xinjiang-Uighur region is close to the border with Pakistan and Afghanistan. Muslim Uighurs, a Turkic-speaking minority in China, resent being ruled by the majority Han Chinese.
China maintains foreign Uighur groups linked to the East Turkistan Islamic Movement are to blame for the trouble in the region. The World Uighur Congress, based in Stockholm, Sweden, disputes the allegations.
Advocates of Uighur self-determination and international human rights groups have said China's heavy-handed security policies in Xinjiang are creating more ethnic tensions.
In October, Chinese authorities blamed Uighurs for a vehicle incident in Beijing's Tiananmen Square in which five people died, including three in the vehicle, and 40 more were injured. In 2009, riots broke out in Urumqi, capital of the region, and about 200 people died.
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