MASSIVE SEARCH

More than 20 aircraft and 40 ships from seven nations are involved in the search. The US Navy said its aircraft had located a previously reported oil slick south of Vietnam and east of Malaysia, but did not find any debris from the plane.

The passenger manifest issued by the airline included the names of two Europeans - Austrian Christian Kozel and Italian Luigi Maraldi - who were not on the plane. Their passports had been stolen in Thailand during the past two years.

An Interpol spokeswoman said a check of all documents used to board the plane had revealed more "suspect passports", which were being investigated.

"Whilst it is too soon to speculate about any connection between these stolen passports and the missing plane, it is clearly of great concern that any passenger was able to board an international flight using a stolen passport listed in Interpol's databases," Interpol Secretary General Ronald Noble said.

Malaysia's state news agency quoted Home Minister Ahmad Zahid Hamidi as saying the two passengers using the stolen European passports were of Asian appearance, and criticising border officials who let them through.

"I am still perturbed. Can't these immigration officials think? Italian and Austrian but with Asian faces," he was quoted as saying late on Sunday.