KUALA LUMPUR (AFP) - Malaysia's leader said on Sunday that airport security screening in the country would be reviewed, according to a report, after it emerged that two passengers who boarded a missing airliner had stolen passports.

Malaysia Airlines flight MH370 vanished over waters somewhere between Malaysia and Vietnam early on Saturday, shortly after taking off from Kuala Lumpur International Airport, and was feared lost with 239 passengers and crew.

"We will review all security protocols and, if needed, we will enhance them," Prime Minister Najib Razak was quoted saying in The Star newspaper.

He stressed: "If necessary, because we still do not know the cause of the incident."

The plane went missing en route from Kuala Lumpur to Beijing. Several Southeast Asian nations have launched searches for wreckage but nothing firm has yet been reported.

A Malaysian civil aviation official said authorities believe two passengers had used stolen passports and were examining CCTV footage of them.

Malaysia's transport minister said earlier Sunday the government was looking into the possibility of a terror incident and was liaising with the intelligence agencies over the countries, including US Federal Bureau of Investigation (FBI).