FACTBOX: Facts about China's restive Xinjiang region

(Reuters) - Police in China's restive Xinjiang came under attack on Monday morning, four days before the Beijing Olympics begin, with 16 officers killed and 12 wounded, state media reported.

Here are some facts about the region.

* Remote northwestern Xinjiang is China's largest provincial-level administrative area. It covers one-sixth of the country, but is relatively sparsely populated with a population of around 20 million.

* It is home to 8 million Uighurs, a Turkic, largely Islamic people who share linguistic and cultural bonds with Central Asia. Many resent the growing Han Chinese economic dominance in Xinjiang, as well as government controls on religion and culture.

* Along with Tibet, Xinjiang is one of the most politically sensitive regions in China, but compared with Tibet's independence cause the movement by some Uighurs to campaign for a separate "East Turkestan" state has received less international attention.

* Xinjiang borders Russia, Mongolia, Kazakhstan, Kyrgyzstan, Tajikistan, Afghanistan, Pakistan and India.

* The area has been at the heart of China's security fears leading up to the Olympics. In March, officials said airline crew foiled an attempted airline bombing on a flight from Xinjiang to the national capital, Beijing. Authorities have repeatedly warned that Uighur militants campaigning for Xinjiang independence may mount attacks.

* The government has accused militant Uighurs of working with Muslim terror group al Qaeda to bring about an independent state called East Turkestan by violent and terrorist means.

* Human rights groups say China has used its support for the U.S.-led war on terror to justify a wider crackdown on Uighurs, including arbitrary arrests, closed-door trials and use of the death penalty.

* Xinjiang has abundant oil reserves and has recently become China's largest natural gas producing region.

Sources: Reuters, Xinhua

(Writing by Gillian Murdoch, Beijing Editorial Reference Unit; Editing by Guo Shipeng and Nick Macfie)