For a second day running a Malaysia Airlines jet carrying 239 people remains missing off southern Vietnam. Investigators are checking identifies of passengers listed. A Texas firm says 20 of its employees were on board.
Search teams scoured waters off Vietnam on Sunday with no confirmed signs of the Malaysia Airlines Boeing 777-200ER which vanished from radar screens early on Saturday. Malaysia said its probe had turned to the plane's passenger list.
Malaysian transport minister Hishamuddin Hussein said his country's investigators were checking the identities of four passengers. Their probe was focusing on the plane's entire list or manifest, he said, adding that the US FBI had been consulted.
At least two passengers on Saturday's MH370 flight appeared to be traveling on stolen passports. China's news agency Xinhua said the persons named, one from Austria and the other from Italy, were still alive and had had their passports stolen in Thailand last year.
Earlier, Malaysia Airlines chief executive Ahmad Jauhari Yahya had declined to state a cause of the plane's disappearance, saying: "We are not ruling out any possibilities."
Semiconductor employees among missing
The US firm Freescale Semiconductor in a statement on its website said 20 of its employees were confirmed passengers on Flight MH370.
Twelve of these were from Malaysia and the other eight from China, said Freescale's chief executive Gregg Lowe, from the firm's headquarters in Austin, Texas.
Two-thirds of the 227 passengers were from China. The other occupants were from other countries in Asia, North America and Europe. Also on board were 12 crew members.
In Kuala Lumpur, family members gathered but were kept away from reporters. At Beijing's airport, relatives and friends were told to gather at a nearby hotel and wait for information.
Vanished at high altitude
The eleven-year-old 777 departed Malaysia's capital early Saturday morning, local time, climbed to 35,000 feet (10,700 meters) and vanished while over waters south of Vietnam.
Weather conditions were good and there was no distress call. Vietnam's civil aviation agency said its air traffic control never made contact with MH370.
Planes and aircraft of several countries continued scouring the area on Sunday.
Malaysian Prime Minister Najib Razak said his country had deployed 15 air force aircraft, six navy ships and three coast guard vessels, adding that it was "too early" to make conclusive remarks.
Vietnam said its rescue planes had spotted oil slicks but were not able to confirm that they were connected to the missing plane.
Hanoi said three Vietnamese search vessels reached the location early Sunday, but found no sign of wreckage.
China and the Philippines also sent ships. Military planes were dispatched by the US, the Philippines and Singapore.
The disappearance of MH370 appeared reminiscent of June 2009 when an Air France flight vanished over the South Atlantic. The wreckage of the Airbus A330 was found only two days later. A total of 288 lives were lost.
Two US accident experts, William Waldock and John Goglia, said separately that the lack of a distress call from the Malaysia Airlines' flight suggested a very sudden incident.
The plane had either experienced an explosive decompression or was destroyed by an explosive device, said Goglia, adding that the 777 was one of the "most reliable airplanes ever built."
The 777, when inspected 10 days ago, was "in proper condition," said another Malaysia Airlines manager, Ignatius Ong.
Boeing 777s entered service 19 years ago. Until July last year, when an Asiana Airlines 777-200ER crash-landed in San Francisco, killing three passengers, the airplane type had been largely accident-free.
ipj/mr (AP, dpa, Reuters, AFP)