A police officer has been killed and his attacker shot dead in Urumqi in Xinjiang, the city government reported.
The assailant, a Uygur, attacked the officer - also a Uygur - at the entrance to a government building, according to an article posted on a news website run by Urumqi authorities. The officer later died from his wounds.
The attacker used a knife and an axe, said another police officer on his Sina Weibo account. He then went to a police station where he was surrounded and shot dead by paramilitary officers, the weibo posting said.
The public security ministry identified the victim as Wusi Manjiang, 29, father of a one-month-old boy.
No motive for the attack was offered. Police are continuing their investigation.
Tensions in the city were already high following violence earlier this month in Kunming in Yunnan province, where a group of assailants went on a rampage and killed 29 people and injured 143 others. Four attackers were killed at the scene, and another was taken into custody.
Beijing blamed Xinjiang separatists, whom it accuses of wanting to establish an independent state called East Turkestan.
Abdullah Mansour, leader of the rebel Turkestan Islamic Party, called the Kunming attack an "expensive offer" for China to reconsider its "cruel" policies in Xinjiang, the SITE monitoring service said late on Tuesday, citing a video by the group.
"Know that blood of those who are killing themselves is not being spilled for nothing, for their blood will bring tens more to carry out jihad."
The Turkestan Islamic Party, which China equates with the East Turkestan Islamic Movement (ETIM), keeps a low profile in Pakistan, where it is holed up in a lawless tribal belt.
Foreign ministry spokesman Hong Lei said Mansour's video "exposes the true nature of their terrorist organisation" with their open support for the Kunming attack.
"Terrorism is the public enemy of mankind. Cracking down on the ETIM terrorist group is an important part of the international community's fight against terrorism," Hong said.
Additional reporting by Reuters