KUALA LUMPUR - Overnight search and rescue operations for the missing Beijing-bound Malaysia Airlines flight MH370 have turned up nothing, the Malaysian authorities said on Sunday.
The Department of Civil Aviation director-general Azaruddin Abdul Rahman said the search is covering an expanded area in the South China Sea area and west coast of Malaysia.
Three aircraft joined the search on Sunday morning.
"We have not been able to locate anything," Mr Azaruddin said at a press conference at Kuala Lumpur International Airport.
He also said there was no confirmation yet if the reported oil slicks found in the area where the plane had vanished were linked to the missing jet.
He declined to give any information on reports that two impostors could have used stolen Italian and Austrian passports to board the flight.
"We are doing investigations. This investigation is into all angles," he said repeatedly when pressed for an answer.
Two men - an Italian and an Austrian - whose names appeared on the passenger list have come forward to say they were not on the flight. Their passports were reported stolen a year and two years ago respectively in Thailand.
This has raised suspicion of a terrorist attack, according to unnamed US officials quoted by the US media. Malaysia has, so far, said it had not ruled out anything.
The Malaysia Airlines flight MH370 lost contact with Subang Air Traffic Control 50 minutes after departing KLIA at 12.41am on Saturday.
It was due to land in Beijing at 6.30am, and had enough fuel to fly up to 8.30am. The plane did not issue a distress signal nor was there bad weather when it disappeared.
The flight was carrying a total number of 239 passengers and crew - comprising 227 passengers (including 2 infants) and 12 crew members.
There were 15 nationalities on board, the majority Chinese nationals and Malaysians. No Singaporeans were on board.
The plane was last on the radar at approximately 120 nautical miles off Kota Baru, in the South China Sea, in the airspace bordering Vietnam. Malaysian air traffic control had just handed over control to the Vietnamese authorities when they lost contact.
The Vietnamese authorities are searching in their waters while Malaysia scoured their own. Other countries involved in the search are China, the Philippines, Singapore and the US.
Malaysia said the search would go on round the clock until a decision was made to call it off.
Flight MH370 was operated on a Boeing 777-200 aircraft, a code share with China Southern Airlines. The plane was 11 years 10 months old.
The next press conference is scheduled at 11am.