"A court in the Xinjiang Uygur Autonomous Region sentenced three men to death and another one to life imprisonment after finding them guilty of attempting to hijack an aircraft in June," the official Xinhua news agency reported from Urumqi, the provincial capital.
The brief report did not give details of the hijack attempt, but authorities said in June that six members of China's Uygur minority tried to hijack a plane that had taken off from Hotan in the far-western region and were thwarted by passengers and crew.
Two security personnel were seriously injured in the incident which occurred on June 29.
Xinjiang, the home of Uygurs, a Turkik speaking Muslim community has experienced ethnic clashes as Uygurs have resented the increasing settlements of the Han Chinese people.
Uygurs allege discrimination and marginalisation and the province has witnessed a number of ethnic clashes and violent incidents since 1990s. In 2009, riots erupted in Xinjiang were followed by a major crackdown.