BEIJING (AP) -- Assailants attacked police and other people with knives and set fire to police cars in China's restive far-western region on Wednesday in violence that killed 27 people, one of the bloodiest incidents since unrest in the regional capital killed nearly 200 in 2009.
The early-morning violence - described by state media as riots - also left at least three people injured in a remote area of the Turkic-speaking Xinjiang region, the official Xinhua News Agency said. Police stations, a government building and a construction site were targeted in the attacks, it said.
Xinhua said the attackers stabbed victims and set fires, killing 17 people including nine police or security officials, before officers shot and killed 10 of the assailants in Lukqun, a township in Turpan prefecture. The agency cited officials with the region's Communist Party committee.
Xinjiang (shihn-jeeahng) is home to a large population of minority Muslim Uighurs (WEE'-gurs) but is ruled by China's Han ethnic majority. The region borders Central Asia, Afghanistan and Pakistan and has been the scene of numerous violent incidents in recent years, including ethnic riots four years ago in Urumqi, the regional capital.
Xinhua did not provide details about the cause of the unrest and it was impossible to independently confirm the report. Information is tightly controlled in the region, which the Chinese government regards as highly sensitive and where it has imposed a heavy security presence to quell unrest. However, forces are spread thin across the vast territory and the response from authorities is often slow.
The United States said it was closely following the reports of violence, and it urged Chinese authorities to conduct a thorough and transparent investigation and to provide due process and legal protections to those detained.
"We remain deeply concerned by the ongoing reports of discrimination and restrictions against Uighurs and Muslims in China," State Department spokesman Patrick Ventrell told reporters in Washington.
An official reached by phone at the press office of the Xinjiang Public Security Bureau, the region's police, said she had only seen news of the violence on the Internet and had no information. Other officials at the county's propaganda department and police said they also had no details. Calls to the region's government spokeswoman, Hou Hanmin, rang unanswered.
Though it remained unclear what caused Wednesday's violence, police stations, government offices and other symbols of Han Chinese authority have been targets of attacks in the past. The attack occurred at 6 a.m., when most residents would still be asleep.
The report said three assailants were seized, and that police pursued fleeing suspects, though it did not say how many. It said three people were injured by the unrest and were being treated.
The violence came two months after a deadly clash in a town near Kashgar, elsewhere in Xinjiang, killed 21 people, including 15 police officers and community workers.
An overseas Uighur activist said Wednesday's conflict was triggered by the Chinese government's "sustained repression and provocation" of the Uighur community.
Dilxat Raxit, spokesman for the Germany-based World Uyghur Congress, said residents he contacted in neighborhoods about 30 kilometers (18 miles) outside the township said the area has been sealed by "armed forces" and telephone services appeared to be irregular. A heavy security deployment and disruption of communications services also followed the 2009 Urumqi riots.
Dilxat Raxit urged the international community to pressure China to "stop imposing policies in Xinjiang that cause turmoil." Many Uighurs complain that Beijing imposes tight restrictions on their religious and cultural life, barring children and women from attending mosques and discouraging fasting during the Muslim month of Ramadan, which starts this year in early July.
Many Uighurs say they suffer discrimination in jobs and cannot obtain loans and passports.
The Chinese government says all ethnic groups are treated equally and point to billions of dollars in investment that has modernized Xinjiang, a strategically vital region with significant oil and gas deposits. Beijing often accuses overseas Uighur activists of orchestrating violent incidents and obscure militant groups sometimes take responsibility, with little or no evidence to prove claims on either side.
Duncan Innes-Ker, an analyst at Economist Intelligence Unit, said the latest unrest shows that the government needs a new strategy to resolve ethnic and religious tensions in Xinjiang.
"Its past efforts to address them with tight security and economic development have been a manifest failure," Innes-Ker said.
The township of Lukqun is about 250 kilometers (150 miles) southeast of Urumqi along the ancient Silk Road connecting China to Europe.
It is part of an area that includes Turpan, a tourist destination with distinctive Central Asian architecture.