The missing Malaysian airlines plane may have been spotted by military radar - hundreds of miles off course.
The country's air force chief says what could have been an airliner was recorded off the country's west coast, after it lost contact with Air Traffic Control.
42 ships and 39 aircraft are now searching an extended area.
Sky's Jonathan Samuels is in Beijing - where the plane was heading when it vanished.
He says updates from officials aren't making the situation any clearer:
David Learmont is an aviation safety expert with flightglobal - he's drawn comparisons in this case with the crash of an Air France flight in 2009.
It took a number of years before investigations determined what happened on board flight 447.
David Learmont says there's simply no definite information on the fate of MH370 yet:
