Missing Malaysia Airlines plane 'may have turned back'
Search teams are still trying to establish what happened to a Malaysia Airlines plane that disappeared south of Vietnam with 239 people on board.
Radar signals show the plane - Flight MH370 from Kuala Lumpur to Beijing - may have turned back shortly before it vanished.
Malaysian officials say they are investigating the identities of two passengers, who were flying on stolen passports.
John Sudworth reports from Beijing.