China has foiled an attempt to crash a passenger jet en route to Beijing and the aircraft made a safe emergency landing, state media and an official said on Sunday.

The China Southern flight originated from the restive northwestern region of Xinjiang. It landed in the northwestern city from Lanzhou on Friday after the crew discovered and foiled the attempt to "cause an air disaster", Xinjiang Governor Nuer Baikeli told reporters on the sidelines of the annual session of parliament.

"Who the people involved in the incident were, where they were from, what their aim was and what their background was, we are now investigating." The official Xinhua news agency said authorities "foiled a planned terrorist attack". There were no casualties or damage.

A source with knowledge of the incident told Reuters that at least two passengers on flight CZ6901 have been taken into custody for questioning. The source, who requested anonymity, said inflammable material was found in the plane's toilet. Repeated calls to the spokesman's office of China Southern went unanswered. Xinjiang is home to 8 million Muslim Uighurs, many of whom resent the growing presence and economic grip of Han Chinese. Some have agitated for an independent "East Turkestan".

A senior Chinese official has warned that Uighurs -- a Turkic, largely Islamic people who share linguistic and cultural bonds with Central Asia -- were plotting attacks on the Beijing Olympics. Oil-rich Xinjiang borders Pakistan, Afghanistan and Central Asia.