Security was heightened in the city of Hotan, northwestern Xinjiang Uyghur Autonomous Region Tuesday, a day after a fatal clash between policemen and rioters at a police station left at least four people dead.
Updated casualty figures were not available as the investigation continued with the assistance of a working team consisting of officials and analysts from the national counter-terrorism office, sources said.
A group of rioters carrying explosive devices and grenades stormed a police station in Hotan on Monday where they killed an armed policeman, a security guard and two hostages, before armed police shot several of them dead and regained control.
Wang Wenhua, deputy secretary-general of the regional committee of political and legislative affairs of Xinjiang, told the Global Times that the overall security situation was under control.
"Local authorities are committed to resolutely combating and taking precautions against terrorism, and handling incidents in a timely fashion," Wang said.
Officials and analysts dismissed rumors that the assault on the government target was "a reaction to oppression by the authorities."
The Germany-based separatist group, the World Uyghur Congress (WUC), asserted Tuesday that the attack was launched after policemen had attempted to clamp down on a "peaceful demonstration" outside the building.
WUC spokesman Dilxat Raxit told AFP that security forces had beaten 14 people to death and shot dead six others during a protest on Monday and arrested at least 70 people.
After police opened fire on demonstrators, a group of Uyghurs tried to seize a number of police officers to use as leverage to demand the release of their family members detained earlier, Raxit was quoted as saying.
The protesters were demanding information on relatives who had been arrested due to deadly unrest in the regional capital Urumqi in July 2009, he claimed.
A total of 197 people were killed in the July 5 riot, mostly of Han ethnicity, and 1,600 injured.
Hou Hanmin, chief of the regional information office, rejected the claim, reiterating that concrete evidence had already indicated that it was an organized attack by well-armed terrorists.
"The assault was clearly targeted. The attackers hurt two people with knives in nearby government offices and headed to the police station right after that," Hou told the Global Times. "They took hostages during their attack so as to raise tensions."
Li Wei, an anti-terrorism expert with the China Institute of Contemporary International Relations, told the Global Times that the way the rioters carried out their assault was typical of a terrorist attack. "They aimed to stir public panic."
"Signs have shown that the rioters were greatly influenced by overseas terrorist organizations. They adopted a complicated approach to the attack and sought to amplify fears among the public," Li said.
"Their aggressiveness in choosing a police station as a target rang the alarm bell for local authorities that grave challenges to security remain," he added.
Pan Zhiping, director of the Institute of Central Asia at the Xinjiang Academy of Social Sciences, told the Global Times Tuesday that with over 90 percent of its residents being of Uyghur ethnicity, Hotan appears prone to the influence of terrorism that has penetrated the country from overseas, and that would result in religion being used as a tool to instigate separatist activities and violence.
"Located in the southern part of Xinjiang, Hotan is close to the border with Pakistan. Due to their affinity in religion and language, some Uyghur residents there are at risk of being influenced by terrorist groups such as the East Turkistan Islamic Movement," Pan said.
Liu Linlin contributed to this story