A Uighur woman crosses a street in front of Chinese soldiers in Urumqi in this file picture dated July 15, 2009

Story highlights

NEW: The World Uighur Congress says 16 people died in Tuesday's rioting

China's Xinhua news agency put the death toll at 12, including two killed by police

Beijing has blamed militants of Uighur descent for outbreaks of violence in Xinjiang in recent years

Uighurs are ethnic Turks distinct from China's majority Han population

CNN  — 

Chinese authorities have made dozens of arrests following a deadly clash between Han Chinese and ethnic Uighurs in the country’s remote northwest, a U.S.-based Uighur leader said Wednesday.

China’s state news agency Xinhua said 12 people were killed in rioting near the northwestern city of Kashgar, including two shot and killed by police during Tuesday’s melee. Xinhua said the trouble began when a group of knife-wielding assailants attacked people in a market.

But Omer Kanat, vice president of the World Uighur Congress, put the toll at 16, including seven members of China’s security forces.

“We have heard different accounts. We don’t know exactly what happened,” Kanat said. But local residents have told the group that the rioting began with a dispute between Uighur youth and Han Chinese settlers in a market, he said.

“The Chinese authorities already launched a crackdown and an arrest campaign after this, and according to our information, 80 people are arrested,” he said. “They are now looking for the people involved in this incident.”

Neither account could be independently verified.

Uighurs are predominantly Muslim ethnic Turks who are linguistically, culturally and religiously distinct from China’s majority Han population. Chinese authorities have blamed Islamic militants of Uighur descent for previous outbreaks of violence in Xinjiang province, where Uighur-Han Chinese rioting in July 2009 left nearly 200 people dead and 1,700 injured.

The massive security clampdown in the wake of the violence has angered many Uighurs, who make up more than half of the 9 million people that live in the far western region of China.

“This crackdown is ongoing,” Kanat said. “They restricted everything, every movement of the Uighurs. So the people are frustrated, and there is no way to express your grievances. Some individuals resort to violence, unfortunately.”

Tuesday’s rioting coincides with the opening of a new 3.64 billion yuan ($579 million) highway linking Kashgar to Yecheng, which lies 155 miles (258 km) to the south.

Beijing says militant Uighur groups linked to the East Turkistan Islamic Movement, a separatist organization it says operates from neighboring Afghanistan and Pakistan, have been fomenting trouble in the region. In December, Chinese authorities killed seven Uighurs in a bid to free two hostages kidnapped in the rural county of Pishan, near Yecheng – an incident the Stockholm-based World Uighur Congress disputes.

The WUC said the deaths occurred when police opened fire on a demonstration outside a police bureau where Uighurs were protesting a recent security crackdown in Hotan city. And authorities in Xinjiang said last month they plan to recruit 8,000 extra police officers as China strengthens security in the run-up to a major leadership transition later this year.

Kanat said additional police “will not work, and there will be more violence.”

“But they are not trying to prevent that violence by listening to the grievances of the people,” he said. “They don’t want to listen to them. They just want to suppress all dissent by force.”

CNN’s Peter Shadbolt contributed to this report.