The Malaysian military says the passenger jet that disappeared last Saturday veered far off course from its intended flight path from Kuala Lumpur to Beijing.
Officials said Tuesday that radar tracked Flight 370 over the Strait of Malacca, hundreds of kilometers to the west of where civilian air traffic controllers lost contact with it off Malaysia's east coast. The strait is one of the world's busiest shipping routes and separates the western coast of Malaysia and the Indonesian island of Sumatra.
The location of the Boeing 777, with 239 people aboard, remains a mystery. It disappeared from civilian radar without any distress calls about an hour after leaving Kuala Lumpur early Saturday.
The head of Interpol says the disappearance of the jet does not appear to be related to terrorism. But John Brennan, the director of the U.S. Central Intelligence Agency, said he would not rule out the possibility.
Interpol Secretary General Ronald Noble said new information about two Iranian men who used stolen passports to board the plane makes terrorism a less likely explanation for the jet's disappearance.
Interpol, the international police agency, released photos showing the two Iranians boarding the plane at the same time. They are identified as 19-year-old Pouria Nour Mohammadi and 29-year-old Seyed Mohammad Reza Delavar.
Malaysian Police Inspector General Khalid Tan Sri says the 19-year-old likely was trying to migrate to Germany.
"We have been checking his background. We have also checked him with other police organizations on his profile, and we believe that he is not likely to be a member of any terrorist group. And we believe that he is trying to migrate to Germany."
The other man's identity is still under investigation. But the development reduces the likelihood they were working together as part of a terror plot.
Aerospace expert Wayne Plucker tells VOA he believes the Boeing 777 jet eventually will be found but that it might take some time.
"This may be a while. Remember that the Air France plane that went down off of Brazil (in 2009), it took quite awhile even though there was apparent wreckage on the surface. "
Plucker said the Boeing 777 has had a good safety record.
"There's nothing that points a finger at a problem. Malaysian Airlines has a good history of maintenance."
The search for the missing jetliner expanded Tuesday, as relatives of those on board prepared to deal with expected bad news.
The search area spans a radius of 185 kilometers from where the jet disappeared, including areas on land.
Dozens of ships and planes involved in the search have failed to turn up any trace of the plane.
Malaysian officials have been exploring scenarios of what may have brought down the Beijing-bound jet, including an explosion, hijackers, pilot error or mechanical failure.
Aviation expert and former commercial airlines and military pilot Jim Tilmon tells VOA's Daybreak Asia locating debris is key to explaining the cause of any crash.
"If the airplane broke up at that altitude, or anything close to that altitude, it would spread debris over a very wide area ... On the other hand, if we have a relatively confined debris field, it may lend one to understand that this airplane was in pretty good shape in terms of being whole as it went into the water."
The speculation has done little to comfort those waiting for information about their relatives. Ms. Wang, whose mother was on the flight, said she is still hopeful.
"As a family member who lost contact with their families, the most concerned issue is to find out their own family members, find out where they are and find out the result. If there is no progress on search and rescue effort, we hope to increase efforts on investigating the possibility of hijacking."
At airports in the region, many travelers remain nervous. Hoo Wee Sin was waiting to board a plane at the Kuala Lumpur International Airport where Saturday's flight took off.
"Frankly speaking, I feel worried about (flying). I feel troubled, too, because it only happened about three or four days ago, so it is not that peaceful actually."
About two-thirds of the people on board were Chinese nationals, with the remainder from other Asian countries, Europe and North America.