|Most Uighurs identify themselves as culturally closer to the nations of Central Asia [GALLO/GETTY]
Although Xinjiang is officially a semi-autonomous region within China, worries over simmering separatist tensions means that Beijing keeps tight control on the region and its native ethnic Uighur population.
Who are the Uighurs?
The Uighur ethnic group are ethnically and culturally a Turkic people who follow Islamic traditions and are based in China's western region of Xinjiang.
There are thought to be about eight million Uighurs in Xinjiang out of a total regional population of about 20 million.
Uighur communities have traditionally been built around agriculture and trade.
For centuries Uighur trading towns such as Kashgar, close to the border with Afghanistan and Pakistan, were important staging posts on the Silk Road trade route linking Europe and China.
What is the history of Uighur separatism?
Although Xinjiang has a long history of Chinese rule, Uighurs have traditionally viewed themselves as having closer cultural and religious ties with the states of Central Asia.
In the early part of the twentieth century Uighurs briefly declared present-day Xinjiang an independent state, known as East Turkestan.
But the region was brought under complete control by Beijing after the communist takeover in 1949.
|Uighur communities have survived traditionally on agriculture and trade [GALLO/GETTY]
In recent years Uighur groups have been waging a largely low-level separatist campaign, with sporadic bombings and attacks on Chinese businesses and symbols of Chinese rule.
Since the 9/11 attacks in the US however, China has increasingly portrayed Uighur separatists as terrorists and says the groups have links to al-Qaeda, although it has produced little evidence to back up those claims.
Human-rights groups say hundreds of Uighurs have been harassed or detained by Chinese authorities after being accused of involvement in terrorism.
Why are the Uighurs opposed to Chinese rule?
Many Uighurs resent what they see as China's repression of Uighur culture and identity, as well as policies they say favour Han Chinese, the dominant ethnic group in China.
|Uighurs say China represses Uighur identity in favour of the Han majority [GALLO/GETTY]
Mosques are routinely banned from broadcasting the traditional call to prayer and communist party officials keep tight restrictions on the appointment and activities of imams, or Muslim priests.
It is also illegal for Muslims to organise their own independent pilgrimage to Mecca beyond the official, state-sanctioned trips.
Uighur groups say Beijing's policy of encouraging ethnic Han Chinese migration to Xinjiang is aimed at diluting Uighur culture and marginalising Uighurs economically.
However, not all Uighurs are entirely opposed to Chinese rule, with several senior Uighurs holding posts in the regional government and communist party, including the Xinjiang chairman, Nur Baekeli.
Why is Xinjiang so important to China?
Xinjiang, an arid and mountainous region, covers a vast expanse of western China, equivalent to about one sixth of the country's total landmass or an area about three times the size of France.
Although sparsely populated it has abundant mineral and oil reserves and is China's largest natural gas producing region.
It also has large reserves of another commodity - space - that is in short supply in China's overpopulated east.
In the 1960s and '70s, Xinjiang was the location for a series of nuclear tests as past of China's atomic weapons programme.
In addition, Xinjiang is strategically located at the borders of Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan and India.