Malaysia plane: Investigation into passengers
9 March 2014 Last updated at 09:55 GMT
Malaysian authorities are co-ordinating with international intelligence agencies over the identities of two of the passengers on board the plane that disappeared on Saturday.
The BBC has confirmed that a man falsely using an Italian passport and a man falsely using an Austrian passport purchased tickets at the same time, and were both booked on the same onward flight from Beijing to Europe on Saturday.
The BBC's Jonathan Head reports from Kuala Lumpur.