The search area for a missing jetliner has expanded with the airline saying the western coast of Malaysia is now the focus of the hunt that is now entering its fourth day.
That is on the other side of the country from where Malaysia Airlines flight MH370 was reported missing.
In a press conference in Kuala Lumpur, Malaysian police authorities said they were investigating every passenger on the list and were looking at four possible scenarios: hijacking, sabotage, psychological problems among passengers or staff, or personal problems.
In a statement on Tuesday the company said the hunt had expanded beyond the flight path, and the "focus is on the West Peninsular of Malaysia at the Straits of Malacca."
Civil aviation chief Azharuddin Abdul Rahman said search teams would continue to look in both areas, the Associated Press news agency reported.
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Vietnam's deputy military chief said he had ordered a land search for the plane up to border with Laos and Cambodia.
The announcements reflect the difficulty authorities are having in finding the plane, which was carrying 239 people when it vanished off radar screens on Saturday.
In the days since, there have been repeated reports of oil slicks being found and possible debris sightings, only for all of them to be later ruled out.
It was announced on Tuesday by Chinese state media that Beijing is deploying about 10 satellites in hopes of tracking down the missing plane.
The high-resolution satellites, which are controlled from the Xian Satellite Control Centre in northern China, will be used for navigation, weather monitoring, communications and other aspects of the search-and-rescue effort, the PLA Daily newspaper reported.
Nearly two-thirds of the 239 people aboard flight MH370 were from China, and if the loss of the aircraft is confirmed, it would be China's second-worst ever air disaster.
Crews from nine countries - China, Malaysia, the United States, Singapore, Vietnam, New Zealand, Indonesia, Australia and Thailand - have joined the international search effort.
The widened search comes after families of passengers reported hearing ringing tones when they tried their relative's mobile phones - leading to speculation that the plane could be on land.
In a separate development, Thai police suspect two men who travelled on the plane using stolen passports were not involved in criminal activity. Evidence suggested they could have been asylum seekers, police said.
Interpol had confirmed on Sunday that at least two passengers on the flight from Kuala Lumpur to Beijing used passports stolen in Thailand within the last two years leading to speculation that the plane had been attacked.
Thai and foreign police investigators have been questioning two travel agents in the resort city of Pattaya, where the tickets were bought for the two men who boarded the flight using the stolen passports.
"We haven't ruled it out but the weight of evidence we're getting swings against the idea that these men are or were involved in terrorism," Pattaya chief of police Supachai Puikaewcome told the Reuters news agency on Tuesday.
Both of the tickets, bought for the travellers by two Iranians, were for travel on from Beijing to Europe at the cheapest price, Supachai said.
"We're looking into all angles including the possibility that these men were involved in human smuggling," he said.