China's Muslim minorities: Uprising from the ashes of history
According to the Chinese government, there are more than 20 million Muslims who live in all parts of the country.
Others say the number may even be higher.
Many Chinese towns have mosques. The call to prayer can be heard on Fridays from Beijing to Yunnan in the south, and especially in the oases of arid Xinjiang in the far northwest.
But there are subtle differences among the communities that follow Islam in China — cultural, linguistic and nationalist nuances that formed over centuries of an often-troubled history.
Muslims have lived in the Middle Kingdom from just after the death of the Prophet Muhammed in 632 AD. They came as traders and missionaries from Arab states, and later from Islamic Persia and Ottoman Turkey.
1st mosque built 1,400 years ago
Tang and Song Dynasty emperors, with an eye on the riches of the Muslim world, made them welcome and even built China's first mosque in what is today the city of Guangzhou.
Descendants of this group are contemporary China's largest Muslim group, known as Hui.
Centuries of co-existence have made many Hui people distinguishable from Han Chinese only by the practice of their faith. When decades of mandatory atheism under Mao Zedong ended in the late 1970s, many devout Hui flourished, reopening mosques and signing up for government-approved trips to Mecca.
The same wasn't true of the country's other large Muslim group, the Uighur people of Xinjiang.
Ethnically, Uighurs — pronounced wee-ghurs — are Central Asian, speakers of a language related to Turkish.
They look west to the Middle East, Turkey and Tashkent, not east to Beijing.
Like the Tibetans on their southern border, they remember when they inhabited a sovereign land and even conquered parts of past Chinese empires in battles centuries ago.
On the northern branch of the historic Silk Route between Mongol China and Rome, the Uighurs traded and travelled widely and forged a distinctive local approach to Islam.
Xinjiang named China's 'new frontier'
But the Chinese have long regarded the region as an integral part of their vast country.
Briefly, in the political chaos that engulfed China in the 1930s and early 1940s, the Uighurs declared independence under the name East Turkestan, but the victory of Mao's communists in 1949 brought them firmly back under Chinese rule.
Zealously atheist Maoists stamped out religious worship of all sorts, although Xinjiang's remoteness and cultural disconnect with Han-dominated China meant Islam survived more openly than elsewhere in the country.
But Uighur discontent with rule from Beijing intensified as the discovery of oil and mineral wealth brought migrants from all over China. The Chinese government encouraged migration with official campaigns with names like "Go West."
A surge in Han Chinese migrants
Today, there are almost as many Han Chinese as Uighur in Xinjiang.
In the 1990s, foreign media began reporting on Uighur grievances and human rights groups highlighted their cultural and religious concerns.
Lacking a charismatic leader like Tibet's Dalai Lama, the Muslims of Xinjiang found little interest in their plight in the west. China opposed Uighur activism as vigourously as its Tibetan version, restricting Islamic teachings and cracking down hard on community leaders and others who advocated sovereignty or civil rights.
The Sept. 11 attacks gave China an opportunity to press its case that Uighur Muslims and independence leaders were affiliated with international Islamist militancy.
The authorities stamped down hard on demonstrations and civil disobedience campaigns and gave frequent news conferences, saying they had stymied plans for terror campaigns.
Despite the crackdown, a deadly attack was launched on a Xinjiang police station in the days leading up to the 2008 Beijing Summer Olympics. Investigators said two attackers drove a truck into a line of jogging officers and then attacked with knives and explosives, killing 16 officers and wounding another 16.
Then, in July 2009, protesters and police clashed in Xinjiang in a riot that left 140 people dead and 828 injured. The demonstrators had gathered to call for justice in the June deaths of two Uighurs.
Experts doubt al-Qaeda links
Chinese state media has often pointed to attacks and unrest as proof that Islamist Uighurs have violent aims in their independence campaign.
Most international experts on jihadist groups say whatever links exist between Uighur militants and the likes of al-Qaeda are relatively recent in origin, as much a product of the crackdown on them as anything else.
The fact is that Xinjiang is regarded by Beijing as one of China's most sensitive regions, and a place with huge economic potential. It borders on some of the country's most important allies and has huge reserves of oil and gas.
While China may pay lip service to cultural and religious freedom, in practice it constrains those rights in the name of social harmony and increasingly, a surging economy. The state appoints religious prayer leaders and restricts the contents of their sermond to topics approved by the authorities.
For now, Uighur dreams of independence and Islam sit uneasily alongside the ambitions of a emerging superpower.