The Boeing 777-200 Flight MH370 that went missing over the South China Sea en route to Beijing from Kuala Lumpur had 227 passengers on board, including five Indians and one Indian-origin Canadian, and 12 crew members.
Planes and ships from six countries today resumed the hunt for the plane that suddenly disappeared from the radar one hour after taking off from Kuala Lumpur Airport on Friday.
The discovery that two passengers were carrying stolen passports raised the unsettling possibility of foul play.
"We are not ruling out anything," the chief executive of Malaysia Airlines Ahmad Jauhari Yahya said in Kuala Lumpur.
Malaysia's Defence Minister and acting Transport Minister Hishammuddin Husseinsaid authorities would screen the entire manifest of the flight.
Officials from Malaysia's Department of Civil Aviation today said they have dispatched three jets to join the massive search and were working with a US company that specialises in disaster recovery to locate the aircraft.
They said the search effort continued overnight to locate the missing plane. But the mission made little progress as they have not traced any wreckage or debris afloat.
"The search and rescue teams are still unable to detect the whereabouts of the missing aircraft" en route to Beijing from Kuala Lumpur, Malaysia Airlines said in a statement.
"The airline is continuously working with the authorities in providing assistance. In fearing for the worst, a disaster recovery management specialist from Atlanta, United States, will be assisting Malaysia Airlines in this crucial time.
A command centre would be set up either in Kota Baru, in Kelantan state or in Ho Chi Minh, Vietnam, as soon as it could establish the location of the missing aircraft, it added.
Singapore has sent two warships and a naval helicopter to help in the search for the plane. China dispatched two rescue ships to join the multi-national teams to locate the flight.
Vietnam sent a boat to investigate a "strange object" spotted by a Singaporean search plane in the area in focus about 90 miles south of Vietnam's Tho Chu Island.
The US has also dispatched a team of experts, including officials from the National Transportation Safety Board, FBI and Boeing, to help authorities probe the missing plane.
The US Navy has dispatched a guided-missile destroyer to the southern coast of Vietnam to aid in the search efforts.
Meanwhile, Malaysian authorities today said intelligence agencies are probing how four persons with fake identities boarded the aircraft and counter-terrorism agencies of other countries have been alerted about it.
The red flags were raised yesterday when it was found that four passengers with suspect identities were able to board the ill-fated Flight MH370.
The weather was fine, the aircraft was cruising and the pilots did not get time to send a distress signal unusual circumstance for a modern plane to crash, experts said.
On two impostors who boarded the flight using passports lost by an Italian and an Austrian, Defence Minister Hussein said, adding authorities would screen the entire manifest of the flight.
He did not mention the nationalities of the other two but said intelligence agencies were in contact with their international counterparts, including the FBI, on the issue.
Italian Luigi Maraldi and Austrian Christian Kozel appeared on the passenger manifest list for Flight MH370. Both claimed they had lost their passport in Thailand and are safe.
"We have also informed the counter-terrorism units of all relevant countries," Hussein said.
"If it is an international network, the Malaysian immigration alone will not be sufficient."
Hussein said the entire flight manifest was also under scrutiny, saying "if there was a security risk, we will look into where the lapse was."
"We do not want to target only the four; we are investigating the whole passenger manifest. We are looking at all possibilities," he added.
The list of passengers on board includes 154 Chinese, 38 Malaysians, 7 Indonesians, 6 Australians, 5 Indians, 4 Americans and 2 Canadians.
"At this point, we have not established if there was a security risk involved (and) we do not want to jump the gun," Hussein told reporters when asked if hijack or terror elements could be behind in the disappearance of the flight.
Inspector-General of Police Khalid Abu Bakar said police have not classified terrorism attack behind the disappearance of the plane but are not ruling out any possibilities.
He said police will investigate all angles and obtain CCTV footage from Kuala Lumpur International Airport.
Malaysian authorities are also looking into the possibility of an air turn back that could have been undertaken by the missing plane, a senior minister said today.
In an air turn back, a plane returns to its airport of origin as a result of a malfunction or suspected malfunction of any item on the aircraft.
"The Boeing 777-200 did not transmit any abnormalities before the ground control centre in Subang lost contact with it," Department of Civil Aviation Director-general Azharuddin Abdul Rahman said.
Besides Vietnam's fleet, Malaysia, Thailand, Singapore, Indonesia, China and the US have deployed a total of 22 aircraft and 40 ships to the area.