The plane landed at an airport Lanzhou in China's northwest province of Gansu following the alert at around 1730 (0930 GMT), state-run news agency Xinhua said, quoting the airline and local security sources

The CZ680 China Southern Airlines flight had originally taken off from Istanbul in Turkey, before its scheduled arrival at Xinjiang's provincial capital, Urumqi. It was on route for Beijing when the alert happened.

The reports gave no further details, and did not say who had made the "terrorist threat".