Terrorist acts are sporadic and decidedly low-tech. Many assailants carry out their attacks by knives.

Xinjiang accounts for one-sixth of China. It's the size of Texas, California, Montana and Ohio combined. It is a vast expanse of rippling desert sand dunes, exotic bazaars, dazzling sunshine and wide skies. Snow-dusted mountaintops and thin rivers gasp through arid plains. It is a place that contains the ancient ruins of Central Asian peoples long forgotten, a place where camels graze on the roadside, farmers get around on donkey carts and bored Chinese soldiers run wind sprints in city streets.

The Chinese have controlled Xinjiang on and off since A.D. 73. In 1933 and again in 1944, Uighurs formed short-lived republics. But China reoccupied Xinjiang for good in 1949. The region is rich in oil and gas and provides a buffer between China and Central Asia. Back then, Uighurs accounted for more than 90% of Xinjiang's population. Hans, China's dominant ethnic group, were about 7%.

Since then, Han settlers encouraged by Beijing have poured into Xinjiang, which tilts the ethnic balance. Today, the government says 41% of Xinjiang's 19 million people are ethnic Chinese, and 46% are Uighur. The rest are Mongols and other minorities.

Although resentment against China runs high, most Uighurs either have been intimidated into silence by China's crackdown or co-opted by the promise of economic rewards for accepting Chinese rule and learning to speak Chinese. (Uighurs speak a Turkic tongue most closely related to the language spoken in Uzbekistan, a former Soviet republic.)

A Uighur middle school teacher, stopping for grilled lamb kabobs at a street stall in the oil boomtown of Korla, says there hasn't been much trouble from separatists since the early '90s. He's happy with the status quo — and with his job as a civics teacher earning $120 a month, five times as much as local farmers.

Xinjiang Muslims favor a less strict interpretation of Islam. Unlike their counterparts in the northern areas of neighboring Pakistan, Uighur women walk the streets of Xinjiang's towns wearing colorful dresses. Some forgo wearing scarves and other head coverings. Men down beer or stronger local spirits at roadside stands. Vigorous dances and romantic songs full of innuendo are part of the Uighur culture.

But the officially atheistic Chinese authorities aren't taking chances. They have banned or restricted Islamic rites, such as the traditional call to prayer that used to be issued fives times a day from the mosques. They have closed Islamic schools and organized "educational" sessions in which 8,000 Muslim clerics have been instructed in government rules and regulations.

Local officials were wary about letting foreign reporters wander around independently during a recent trip. Police shadowed reporters and sometimes questioned the people who spoke with them. An organized news conference at the Resten mosque in the Silk Road oasis town of Kuqa occasionally fell into an awkward silence when local imams were asked about religious restrictions and separatist activity. Few will speak openly in favor of separatism, knowing it would likely lead to detention by the Chinese authorities. That's because it is illegal to advocate for an independent Xinjiang, even one achieved by non-violent means.

The Chinese say the terrorist threat, though limited, is real. Small numbers of Uighurs fighting with al-Qaeda in Afghanistan have been captured or killed in the U.S.-led war there. Communist leader Wang says 1,000 Uighur separatists trained at al-Qaeda and Taliban bases in Afghanistan: 400 have been captured — about 20 of them killed — and 600 are still at large.

China reported earlier this year that Islamic separatists have been responsible for more than 200 terrorist attacks and more than 160 deaths since 1990.

The extremists appear to have little support, although many Uighurs are unhappy with Chinese dominance of the region. The Chinese take top jobs in government and business.

Uighurs who want to get ahead must adapt, and some do. Radil Abla spent two years learning Chinese before launching his own food supply business and supermarket chain in Urumqi. Now, he says, he's worth at least $120,000, partly because the Chinese government let him skip income taxes eight straight years. The average income here is less than $1,000 a year. Not surprisingly, he is grateful: "When you drink the water, you should not forget who dug the well."

But a social gulf divides most Chinese and Uighurs. Chinese migrants complain that most Uighurs don't speak their language. And many Uighurs see the Chinese migrants as intruders, although they mostly keep their complaints to themselves.

One Uighur who dared to be an exception stopped briefly on an Urumqi street to tell outsiders he didn't like the Chinese. Why not? "Because I am a Uighur," he said, disappearing into the darkness.