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.
A floating "yellow object" discovered in the sea is not a life raft from the missing Malaysian Airlines jet, Vietnam's civil aviation authority has said.
"It has salvaged the object, at the notice and request by Malaysia's rescue centre, 130 km southwest of Tho Chu island. The object has been identified as a moss-covered cap of a cable reel," the civil aviation authority of Vietnam said on its website.
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.