The mystery surrounding the disappearance of a Malaysian plane with 239 people aboard deepened today with multinational search teams still unable to find the debris from the missing aircraft after over two days.

"Unfortunately, we have not found anything that appears to be objects from the aircraft, let alone the aircraft itself," Azharuddin Abdul Rahman, head of Malaysia's Department of Civil Aviation, said at a televised news conference.

The Beijing-bound Boeing 777-200 flight of Malaysia Airlines had 227 passengers aboard, including five Indians and one Indian-origin Canadian, and 12 crew members.

Vietnamese searchers on ships worked throughout the night but could not find a rectangle object spotted yesterday that was thought to be one of the doors of the plane.

Rahman said Vietnamese officials had not confirmed to Malaysia, reports that debris believed to be from the plane had been found.

He stressed that authorities were looking into all angles and aspects that could have led to the disappearance of the aircraft including hijacking.

Malaysia yesterday launched a terror probe into the disappearance of MH370 flight that suddenly vanished from the radar one hour after taking off from Kuala Lumpur Airport on Friday midnight.

The probe was launched after it emerged that two passengers boarded the flight with stolen passports. Preliminary investigation also indicated that plane may have turned back.

Five passengers holding tickets had failed to board that flight, Rahman said.
"Their luggage was off loaded and would not have been in the plane. All check in luggage was screened," he said.

Home Minister Ahmad Zahid Hamidi yesterday said the two passengers who used stolen passports to board the plane had "Asian facial features".

"I am still puzzled how come (immigration officers) cannot think, an Italian and Austrian (passengers) but with Asian facial features," he told reporters yesterday.

Asked about how the two passengers with Asian features could have been allowed to pass, Rahman said the investigating officials were looking into it and added that authorities were going though all video footage and records.

"There are a number of reports, number of sightings that we have made. The Malaysian Maritime Enforcement agency also spotted slicks in the South China Sea and they took samples of it and those samples have been sent to the labs," Rahman said.

The Malaysian official said the authorities were as "puzzled" as others over the mysterious disappearance of the plane and stressed that search efforts had been intensified expanding area of search to the Andaman sea.