The missing Malaysian Airlines plane probably landed in the Strait of Malacca, where the Malaysian military believes it last tracked the jetliner by radar, and far from where it last made contact with civilian air traffic control off the country's east coast, reports quoting military sources said.
The Strait of Malacca is one of the busiest shipping lanes in the world and it would be much easier to find the debris here.
Search and rescue teams will now start searching the Strait for the first time after three days of searching in the South China Sea.
Search for the missing Malaysia Airlines Boeing 777-200ER, now in its fourth day, has so far found no trace of the aircraft or the 239 passengers and crew.
Search countries from 10 nations and seven Chinese satellites are scouring the seas to unravel the baffling mystery of the missing jetliner.
"It changed course after Kota Bharu and took a lower altitude. It made it into the Malacca Strait," a Reuters report quoted a military official as saying.
Malaysian Airlines officials say they lost radio and radar contact with Flight MH370 off the east coast Malaysian town of Kota Bharu on Saturday.
Meanwhile distraught relatives of the passengers holed up in a hotel in Beijing are not yet convinced that their relatives might have died. Some are convinced their relatives are still alive and authorities are wasting time.
At least one man said his kid's cell phone was not turned off and it was still ringing.
Police is also said to be investigating the possibility of hijack, sabotage or mechanical failure and are looking for the personal traits of passengers and crew on the plane for clues.