The deadliest unrest in China's western Xinjiang region in four years is drawing attention to long-running tensions between the area's ethnic Uighurs and its Han Chinese rulers.
The state-run Xinhua news agency said 27 people were killed in a riot early Wednesday in Xinjiang's Shanshan County. It said unidentified rioters stabbed people and set fire to police cars, killing nine security personnel and eight civilians before police opened fire and killed 10 assailants.
It was the highest reported death toll from a violent incident in Xinjiang since ethnic riots involving Uighurs and Han Chinese killed about 200 people in the regional capital, Urumqi, in 2009.
Since then, there has been sporadic but deadly violence. Most recently, in April of this year, 21 people were killed in Kashgar during a confrontation between Chinese police and Uighurs. Most of the dead were Uighurs.
The Uighurs are a Turkic-speaking ethnic group indigenous to Xinjiang, a Chinese autonomous region that some refer to as East Turkestan. Most Uighurs are Muslims, while a small number are Christians.
The Chinese government says Uighurs make up about 45 percent of Xinjiang's population, while about 40 percent of residents are Han Chinese who have settled in the region for decades.
The Uyghur American Association
, a Washington-based advocacy group, disputes those figures. It says the number of Han Chinese is much higher than officially reported, likely accounting for around 50 percent of Xinjiang's population.
Han Chinese settlement long has been a source of resentment for Uighurs, who accuse Beijing of turning them into a minority in their homeland and suppressing their culture and economic opportunities.
The Chinese government has increased investment in Xinjiang since 2009 to deal with what it considers to be the root cause of the ethnic tension: poverty.
Xinjiang Communist Party Chief Zhang Chunxian also has said it is Chinese government policy to protect the legitimate practice of religion. At the same time, he has pursued a years-long security crackdown against Uighurs whom authorities accuse of using Islam to incite violence.
Uyghur American Association president Alim Seytoff said Beijing is ignoring the legitimate grievances of Uighurs.
"We see from (Wednesday's) unfortunate violence, and from recent instability in the region, that the Chinese government's method of using force and money to buy stability is not working. So China should change this highly intense repressive policy," he said.
Xinhua did not immediately identify the rioters responsible for Wednesday's violence in Shanshan's Lukqun township, saying police were investigating and chasing suspects.
But, Chinese authorities said April's violence in Kashgar involved Uighurs whom it labeled "separatists" and "terrorists." Beijing has blamed much of Xinjiang's unrest on Pakistan-trained Uighurs belonging to the banned East Turkestan Islamic Movement (ETIM).
Last year, Xinjiang's number-two leader Nur Bekri said Xinjiang extremists have "a thousand and one links" to Taliban militants in Pakistan.
Seytoff denied that any Muslim fundamentalists operate in Xinjiang. "This is the usual fabrication of the Chinese government to justify heavy handed repression. Instead of (acknowledging) its repressive policies as the root causes of instabilities here, the government is blaming the religious faith of the Uighur people."
The U.S. State Department designated ETIM as a terrorist organization
Terrorism analysts have said Washington obtained information about ETIM from Uighurs who were captured in Afghanistan and Pakistan after the 2001 terrorist attacks on the United States and then transferred to the U.S. detention center in Guantanamo Bay, Cuba.
Most of those Uighurs have since been released, indicating that U.S. authorities determined they were not members of any terrorist organization. The detainees have been resettled in places such as Albania, Bermuda, El Salvador, Palau and Switzerland.
Beijing had demanded the repatriation of the Uighurs from Guantanamo, but Washington refused, saying it believed they would face almost certain persecution in China.
U.S. State Department spokesman Patrick Ventrell said Wednesday the Obama administration is "closely following" reports of Xinjiang's latest violence.
"We urge Chinese authorities to conduct a thorough, transparent investigation of this incident to provide those detained the due process protections to which they are entitled under China's constitution, laws, international human rights commitments," Ventrell said.
He also said Washington remains "deeply concerned" by what he called "ongoing reports of discrimination and restrictions" against Chinese Uighurs and Muslims.
Seytoff said tension is likely to remain high in the region in the run up to July 5, which will mark the fourth anniversary of the start of the 2009 riots.
"The Chinese government already has initiated a lot of pre-anniversary clampdowns, house to house searches and detentions of people," he said.