Beijing - Chinese authorities accused 'terrorists' in China's far west of setting a trap to kill policemen, state media said on Thursday, after a US-based rights group dismissed terrorism claims.
Twenty-one people were killed in violence in west China's Xinjiang region on Tuesday, local government officials said, adding that six members of the ethnic Uighur minority shot dead in the clashes were suspected of terrorist plotting.
"The terrorists may have set a trap," the state-run Global Times daily quoted local officials as saying, adding that knife-wielding men ambushed police after luring them to a house in Barchuk county, in the region's west.
Fifteen police and 'social workers' were killed in the incident, including 10 from the Uighur minority, China's Foreign Ministry said. Uighurs are mostly Muslim and see Xinjiang as their homeland.
Xinjiang, a region about twice the size of Turkey, is home to around nine million ethnic Uighurs, many of whom complain of religious and cultural repression by Chinese authorities. The region is regularly hit by unrest.
The Uyghur American Association, which is run by members of the minority living in the US, urged the international community to "dismiss" China's claims of terrorism, which it said should be viewed with "extreme caution".
Chinese government claims have not been independently verified, the group said in a statement, and accused local authorities of abusing terror charges to repress Uighurs.
"They always use such labels to justify their use of armed force," the statement quoted Dilshat Rexit, a spokesperson for the World Uyghur Congress, another exile group, as saying.
Officials and state media blame the unrest on "terrorists" but some experts say the government has produced little evidence of an organised terrorist threat, adding the violence stems more from long-standing local resentment.
The US on Wednesday urged China to conduct an independent investigation into the incident, and said that the US ambassador to China visited the region this week as part of a US trade delegation.
State Department spokesperson Patrick Ventrell called on China to "take steps to reduce tensions and promote long-term stability in Xinjiang".
"We urge the Chinese authorities to conduct a thorough and transparent investigation of this incident and to provide all Chinese citizens - including Uighurs - the due-process protections to which they're entitled," he said.
According to official figures, 46% of Xinjiang's population is Uighur, while another 39% are Han Chinese, after millions moved to the area in recent decades.