Police attempting to detain criminal suspects in Shufu county near the Silk Road city of Kashgar, deep in far western China, were attacked by several "thugs" armed with explosive devices and knives, reported the tianshannet news portal, which is run by the Xinjiang government.
Two police officers were killed and 14 of the "thugs" shot dead on Sunday, it said, adding that two criminal suspects were detained.
The incident comes less than two months after an attack in Tiananmen Square, the symbolic heart of the Chinese state, when according to police, three Xinjiang Uighurs ploughed into crowds of tourists, killing two people and injuring 40, before crashing outside the Forbidden City and setting their vehicle ablaze.
The three attackers -- named by authorities as Usmen Hasan, his wife and his mother -- all died.
Beijing described the assault, the first blamed on Uighurs outside Xinjiang, as "terrorism" and said separatists backed by the militant East Turkestan Islamic Movement were responsible.
But outside experts pointed to the unsophisticated nature of the attack and the lack of an established Islamist extremist foothold in China.
Xinjiang, a vast area bordering Pakistan and Central Asia in China's far west, beyond the furthest reaches of the Great Wall, has followed Islam for centuries.
For years it has seen sporadic unrest by Uighurs which rights groups say is driven by cultural oppression and intrusive security measures but China attributes to extremist religion, terrorism and separatism.
A total of 11 people -- nine attackers and two auxiliary police officers -- were killed in an attack on a police station in Serikbuya township near Kashgar last month, according to the official Xinhua news agency.
Another incident in June left 35 people dead, and 139 people have been arrested in recent months for spreading jihadist ideology.
More than 190 "terrorist" attacks were logged in Xinjiang last year, rising "by a significant margin" from 2011, state media reported last month.
Most of the attackers were in their early 30s or younger and increasingly act in small groups or individually as "a lone wolf", it added.
Information in the area is tightly controlled and difficult to independently verify.