Despite tight state control over Islam - imams are paid and vetted by the Government - there are too many mosques in Xinjiang to enforce a mass closure, said Barry Sautman, who specializes in China's ethnic politics at the Hong Kong University of Science and Technology. There are 23,000 mosques in Xinjiang, the highest mosque-to-Muslim ratio in the world, and that provides room for some anti-Goverment critics to slip through, said Sautman.

"It's impossible to control such an extensive number of religious personnel," Sautman said. In rural areas, he said, many officials in charge of religious affairs are Uighurs and are more sympathetic to Islam.

The violence in Urumqi (pronounced uh-ROOM-chee) began Sunday when Uighurs clashed with police while protesting the deaths of Uighur factory workers in a brawl in another part of the country.

The crowd then scattered throughout Urumqi, attacking Han Chinese, burning cars and smashing windows. Riot police tried to restore order, and officials said 156 people were killed and more than 1,100 were injured.

Other cities in Xinjiang, such as Kuqa, where bombs were set off before the Olympics last year, said mosques opened as normal.

The official Xinhua News Agency quoted the director of the Urumqi Civil Affairs Bureau, Wang Fengyun, as saying that families of innocent civilians killed in Sunday's riot would each receive 200,000 yuan (about $30,000) for each fatality.