Kuala Lumpur (AsiaNews/Agencies) - Malaysia Airlines flight MH370 "is an unprecedented missing aircraft mystery," said Azharuddin Abdul Rahman, Malaysia's Civil Aviation chief.
In fact, so far, nothing has been found that could explain why the plane en route to Beijing from Kuala Lumpur disappeared Saturday without leaving a trace.
However, Malaysian intelligence sources said they identified one of the people who used a stolen passport to get on the plane - two passports, one Austrian and one Italian, are known to have been used by passengers to board the aircraft.
Khalid Abu Bakar, inspector general of police, said that the passenger was a foreign national, who was recognised thanks to airport CCT cameras.
However, no further details were provided about the nationality of the people using the stolen documents or how they entered Malaysian territory.
Meanwhile, search operations to find the plane continue, involving some 20 aircrafts and 40 ships from 7 different countries, including Vietnam, Malaysia, China, the United States and the Philippines.
Given the huge area, over thousands of square kilometres of sea, finding anything remains a major task.
Malaysian authorities did not rule out the possibility of a terrorist attack or hijacking because of the presence of at least four suspicious passengers. Malaysian police left open the possibility of hijacking, because some flight indicators show that the plane may have been turning back before it disappeared from the radar.
The lax security at Kuala Lumpur airport has come in for a lot of criticism, especially from the Chinese government, because of the two passengers who were able to board the plane using stolen passports that were listed in the Interpol database.
Some samples taken from oil slicks in the South China Sea were sent for testing to determine if they came from the missing plane. However, Vietnamese authorities denied reports, claiming that pieces from the Boeing 777 had been found.
No one has either confirmed or denied allegations that the plane was downed by an explosion, but for the past three days, relatives of the missing passengers have been told "to prepare for the worst".
Malaysian King Abdul Halim Shah Mu'adzam extended his condolences on behalf of his country to the victims and their families.
Still, China's Foreign Ministry showed its irritation calling on Malaysian authorities to provide further answers about the plane's fate.
Criticising Malaysia for not responding swiftly during the initial stages of the problem, the Global Times Chinese edition said the incident shows there were "obvious loopholes in security checks" in Malaysia.
Similarly, "The fact that some of the passengers on board were travelling with false passports should serve as a reminder to the whole world that security can never be too tight, at airports in particular," the China Daily wrote.
The Boeing 777-200 carried 239 people, including a crew of 12, disappearing over the sea, just south of Vietnam.
The passenger list included 153 Chinese, 38 Malaysians, 12 Indonesians, as well as some Australians, Europeans and Americans.
Malaysia Airlines has had a good safety record, with nearly four decades without an accident. Its worst accident occurred in 1977 when one accident left 100 people dead.
In recent years, the company lost revenues due to the competition from low-cost airlines, including Air Asia, another Malaysia-based company.
Every day, Malaysia's national carrier flies nearly 37,000 passengers to some 80 destinations worldwide.
On Monday, shares in Malaysia Airlines fell 18 per cent to a record low.