KUALA LUMPUR, March 9 -- A China-bound Malaysia Airlines plane may have turned back before it went missing from radar screen, a Malaysian civil aviation official said Sunday.

The Malaysian authorities are also investigating two passengers that had used false passports to board the plane, department of civil aviation director general Azharuddin Abdul Rahman said.

A Malaysia Airlines Boeing 777-200 passenger plane with 239 people onboard, including more than 150 Chinese, lost contact with air traffic controllers en route from Kuala Lumpur to Beijing early Saturday.

There are still no confirmed information about the fate of the plane after about 36 hours passed.