Nearly four days have passed since Malaysia Airlines Flight 370 vanished, and authorities have now widened their search for the plane beyond its flight path.
Rescue teams are now scouring the Gulf of Thailand, the South China Sea and the west coast of Malaysia.
The expansion of the search area came after China pushed Malaysian authorities to step up search efforts for the missing airliner.
Two-thirds of the plane's passengers were Chinese.
A total of nine countries are now participating in search operations.
On Monday crew members of a Cathay Pacific bound for Kuala Lumpur spotted large debris on the southeastern coast of Vietnam.
Authorities, however, have yet to confirm that the debris is part of the missing aircraft.
As for what brought the plane down, authorities haven't ruled out any possibilities, including a terrorist attack.
"We are still looking into the case mentioning the possibility of a terror attack is not appropriate."
As for two of the passengers on Flight 370 that were flying on stolen passports, Malaysian police say one of them has been identified as a 19-year-old Iranian.
They don't believe he has any links to terrorist groups, and think he was trying to make it to Germany to seek asylum.
Malaysia Airlines Flight 370 took off from Kuala Lumpur on Saturday but vanished from radar en route to Beijing.
There have been sightings of oil slicks and pieces of debris, but international efforts to find any wreckage have failed, this despite 40 ships and nearly three dozen planes taking part in search operations.
Connie Kim, Arirang News.