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 families of the 239 passengers on board the missing Malaysia Airlines flight continue to wait for news on loved ones.
Earlier, a floating yellow object and an oil slick seen in the sea were ruled out as possible links to the disappearance.
Authorities have said they are extending the search area in a bid to locate the aircraft which has been missing since the early hours of Saturday.
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.