The Xinjiang region is China's 'wild west', complete with a restive population, an influx of settlers and the promise of riches from natural resources. For China, the region is a strategic buffer zone on its western border and a part of the nation's sovereign territory since the Qing dynasty (1644-1911). After 1949, Xinjiang provided land for crops and people. Critics point out it was also China's penal colony and nuclear testing site. To the Uygur ethnic group, Xinjiang is their homeland. Tensions between Uygurs and their Han Chinese rulers have caused periodic outbreaks of protest and violence, which Beijing considers to be terrorist acts. 'Understand that Xinjiang must not be separated from our homeland's great territory,' reads a sign in a museum in Kashgar, underlining the government's stance. The scale of support among Uygurs for a separate state is not known. Yet both Han and Uygurs seem keenly aware of the differences between the two groups. Sitting outside a mosque in Tuyoq village on the outskirts of Turpan , an elderly Uygur waved his hand in dismay at the Putonghua word for 'thank you' and gave the word in his native language. Another villager, Omir, explained some of the differences that forbade him from marrying a Han woman. 'My parents wouldn't allow it. There is a difference between Chinese and Uygur culture for food and religion,' he said. Uygurs follow Islam and thus abide by Muslim dietary restrictions. Uygurs also speak a Turkic language. China has started requiring the region's schools to teach Putonghua from kindergarten, in an effort to encourage assimilation. 'Chinese is a foreign language to me. We weren't interested in learning Chinese in school,' Omir said. A young boy, Xadiyar, has learned Putonghua so well that he now stumbles in his native language, one sign of how Uygur culture is disappearing. 'It's hard to remember words. Sometimes I forget,' he said. His mother believes learning Putonghua will make it easier for him to find a good job. Omir offered an interesting theory that Uygurs had a different body type from Chinese because they ate mutton. Uygurs trace their ancestry to Indo-Europeans. 'If I say I am Chinese, I have no problems. But I am not Chinese,' he said. Another Uygur, a native of Aksu, explained the difference in the most basic terms. 'We wear hats. Chinese don't wear them,' he said, referring to the skullcaps worn by men. Although some Uygurs openly agitate for a separate state, there are smaller acts of defiance. Kashgar businessman Kaze, who is in his 60s, proudly showed off his eighth child just metres from a banner calling for people to obey family-planning policies. 'That's why I need such a big house,' he said with a laugh. The government allows Uygur couples to have three children if they live in rural areas and two for urban dwellers. Most on the mainland are limited to just one child. There is a traditional desire to have male offspring, so some couples keep having children until they have a boy. 'Loving daughters is heeding the future of the nationality,' reads a propaganda sign in Kashgar, in an attempt to discourage the practice. Modernity is encroaching on Xinjiang. The region has the highest rate of HIV infection on the mainland, according to a United Nations agency, in part because of intravenous drug use. 'Preventing Aids, you and me participating together,' said another sign in Kashgar in both Chinese and Uygur. Xinjiang is bordered by Afghanistan, which produces opium poppies for much of the world's heroin. Environmental degradation is also taking its toll on Xinjiang, with annual sandstorms becoming more frequent. Tian Changyan , head of the Xinjiang Institute of Ecology and Geography, largely blames human factors such as land reclamation, deforestation and overgrazing for the worsening situation. 'The fundamental reason for the situation is the worsening human abuse of the ecological environment, an abuse that can be divided into natural factors and human factors. It is usually the interaction that causes damage to the environment with irreversible consequences,' he said. Beijing has poured massive funding into Xinjiang, building infrastructure and developing oil and gas fields, to encourage economic growth and to pacify the local population. 'The economy is good now, so life is good,' Omir said. However, human-rights groups and Uygur activists claim the benefits are not reaching the ethnic group but tend to favour Han Chinese. One academic has suggested the focus should be more than just economic development. 'We need to enter into a larger perspective, a deeper humanist concern, a more diverse understanding and sense of empathy so as to nurture more harmony among ethnic groups,' said Yao Dali , a professor at Shanghai's Fudan University. Chinese is a foreign language to me.