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.
Vietnam has sent another plane to check the area where Chinese satellites showed objects that could be debris from a missing Malaysia Airlines jet, Vietnamese military officials said.
"We are aware and we sent planes to cover that area over the past three days," Deputy Transport Minister Pham Quy Tieu said. "Today a (military) plane will search the area again,"
Another military official said Vietnam was waiting to see photographs taken by a Chinese satellite on Sunday in waters northeast of Kuala Lumpur and south of Vietnam in order to identify the exact location for further inspection.
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.