China's state news agency on Sunday reported a bomb threat on a plane from Afghanistan scheduled to land in Xinjiang, the restive western region of China that was rocked by ethnic riots last month.
Xinhua News Agency earlier said the incident was a hijacking. It did not identify the airline, but said the Urumqi airport has been told not to allow the plane to land.
Xinhua said police and emergency vehicles have been rushed to the airport.
The region saw the worst ethnic violence in China in decades last month when deadly rioting in Urumqi, Xinjiang's capital, killed 197 people and injured more than 1,700, according to official count.