An aircraft bound for Urumqi in China's restive Xinjiang region has been threatened with a bomb attack, BBC reports according to Chinese state news agency Xinhua.
Officials told the airport not to allow the plane to land, Xinhua said. Later reports said the plane had landed in Afghanistan.
Xinhua earlier reported the incident as a hijacking.
It did not specify whether the threat to the plane came from on board in its latest report.
The incident comes a month after about 200 people died in ethnic violence in Xinjiang's regional capital, Urumqi.
Deadly clashes erupted between Han Chinese and the region's Muslim Uighurs, some of whom want greater autonomy from China.
Since then China has maintained a heavy security presence in the region.