A mob carrying knives and axes targeted civilians, a police station, government offices, and vehicles in Shache County, located in China's Xinjiang Uighur Autonomous Region.
It is unclear how many civilians were killed in the attack.
Police responded to the unrest with force, fatally shooting dozens of assailants.
The region is familiar with instability, where tensions between Uighur Muslims and Chinese Han are high.
Xinjiang is an expansive area of China that was traditionally inhabited by the Muslim Uighurs, Kazaks, and some smaller groups. During the last two decades, however, there has been an influx of Han Chinese migrants Resentment against Han Chinese political and cultural domination simmers and sometimes erupts into violence.
In December, nine people attacked a police station with explosives and incendiary devices in Shache County; eight of the attackers were shot and killed by police.
In March, men wielding knives killed 29 people and injured 130 others at a train station in Kunming. Three people were killed in April during an attack at a train station in Urumqi. Another 39 were killed in an attack on an Urumqi market in May.