An "electronic ping" was picked up from the Malaysia Airlines flight by satellites after the plane lost contact with ground control, Reuters reports. Meanwhile, US officials have been given an "indication" the plane crashed into the Indian Ocean.
The search for the Malaysian airliner has entered its fourth day as authorities step up efforts to locate the missing plane.
Officials are now focusing their search on a large part of the Gulf of Thailand and the South China Sea, while searches are also being conducted on the western coast of Malaysia and up towards the Andaman Sea.
The massive operation involves navies and military aicrafts from 10 nations but so far efforts to establish what happenned to flight MH370 have proved fruitless.
A mother has described her frustration as she waits for answers on the fate of her missing son who is on board the missing Malaysia plane.
Malaysia's military believes a jetliner missing for almost four days turned and flew hundreds of kilometres to the west.
The wife of a passenger travelling on the missing Malaysia Airlines flight has spoken of her struggle to cope as she waits for news.