The plane returned safely to the airport in Hotan city -- which has seen violent clashes between mainly Muslim Uighurs and police due to simmering ethnic tensions -- and the six have been detained, they said.

"The six hijackers are Uighurs," Hou Hanmin, a spokeswoman for the government of Xinjiang told AFP.

"For the moment, we don't know the purpose of the hijack. It's still under investigation," she said, adding at least seven crew members and passengers had been injured in the incident.

The aircraft took off at 12:25 pm (0425 GMT) from Hotan, then 10 minutes into the flight the six suspects tried to "violently hijack" the plane, according to tianshannet.com, the Xinjiang government's news website.

But crew members and passengers soon brought them under control and the aircraft returned to the city, the website said.

The plane had been bound for the Xinjiang capital of Urumqi.

Xinjiang is home to around nine million Uighurs, many of whom complain of religious and cultural repression by Chinese authorities -- a claim the government denies -- and the region is regularly hit by unrest.

Twelve children were injured this month when police raided an Islamic school in Hotan, amid an escalating crackdown by authorities on "illegal" religious activities.

And in July last year, 20 Uighur protesters were killed in Hotan in a clash with police.