Thousands of mostly Han Chinese watched the torch pass through the city of Shihezi, one of the command centres of the Xinjiang Production Corps, a military unit that has spearheaded China's "liberation" of the restive region.

"Shihezi is a new city reclaimed by the military and populated by, designed by, and built by the military," Song Zhiguo, the city's top communist official, said at the start of the relay.

"Through the Olympic torch relay, we can fully display Shihezi's vibrant environment and the results of our military's uniquely beautiful cultivation of this area."

Thursday's Olympic relay marked the third and final day that the torch passed through Xinjiang, a region predominantly populated by Uighurs, a Turkic-speaking people with little resemblance to the Han Chinese.

Shihezi in northern Xinjiang is largely built on reclaimed desert land and boasts a population of 640,000 people, of which just under six percent are an ethnic minority, the Shihezi government website said.

"We must make serious efforts to prevent Xinjiang independence forces and terrorists from sabotaging the Beijing Olympic torch relay," the Production Corps News quoted He Qiang, the city's chief of police, as saying at a security meeting on Wednesday.

The flame's travels through Xinjiang and the Tibetan regions of China are considered the most sensitive legs on the three-month journey to the August Beijing Games because of simmering discontent among ethnic groups.

After starting out in the Xinjiang capital of Urumqi on Tuesday, the flame passed through the oasis Silk Road trading town of Kashgar on Wednesday.

Later Thursday, the flame made its final stop in the region at the mountain resort town of Changji, just northwest of Urumqi.

On Saturday, the flame will travel to Lhasa, the capital of the Tibetan region, where deadly anti-China riots erupted in March.

According to the Germany-based World Uighur Congress, an exile group that advocates creating an independent East Turkestan in Xinjiang, China stations up to 2.5 million soldiers there, acting largely as a colonial force.

"The role of the Xinjiang Production Corps is to oppress the ethnic Uighur nationality and safeguard China's long-term colonisation of East Turkestan," congress spokesman Dilxat Raxit told AFP.

The sensitivity of the Xinjiang leg was heightened earlier this year when Beijing said it had smashed Xinjiang-based terror plots targeting the Games.

Uighurs widely dismiss such Chinese claims as an attempt to justify strict control of Xinjiang, Raxit said.

"Uighurs are living in a culture of fear, facing persecution, marginalisation and assimilation that erode the very core of their cultural identity, religious belief and economic rights," he said.