Chinese police have reportedly shot dead dozens of members of a knife-wielding terror gang in the far western home to the country's Muslim Uighur minority.
"A gang armed with knives and axes attacked a police station and government offices" in Shache county, Xinjiang, early on Monday, the official Xinhua news agency says.
Some then moved to a nearby township "attacking civilians and smashing vehicles as they passed. Dozens of Uighur and Han civilians were killed or injured", the report said.
Local police called it an "organized and premeditated" terror attack, Xinhua said citing initial investigations.
"Police officers at the scene shot dead dozens of members of the mob," it added.
More than 20 Uighur people were killed by armed authorities while 10 were injured, said Dilxat Raxit, a spokesman for the World Uyghur Congress (WUC), citing a local source.
A total of 13 armed Chinese personnel were killed and injured, he said, adding that about 67 people were arrested.
The Uighurs were "resisting China's extreme repressive policy" when they were met with violence, he added.
It is not unusual for there to be a time lag in the official reporting of violence in Xinjiang, especially when they involve clashes with police.
Beijing commonly blames separatists from Xinjiang for carrying out terror attacks which have grown in scale over the past year and spread outside the restive region.
Among the most shocking incidents was a market attack in Xinjiang's capital Urumqi in which 39 people were killed in May, and a deadly rampage by knife-wielding assailants at a train station at Kunming in China's southwest in March, which left 29 dead.