Australian Prime Minister Tony Abbott: "The first [is a] grey or green circular object, and the second an orange rectangular object". Photo: BBC NEWS

The objects could be picked up in the southern Indian Ocean in a few hours, Malaysia's transport minister said.

One object was circular and grey or green, and the other rectangular and orange, Australian PM Tony Abbott said.

Mr Abbott said it was not known whether the objects were from flight MH370, and could be flotsam.

The two objects were different, he said, from several white, square-shaped objects spotted earlier by Chinese military planes.

"The Australian Maritime Safety Authority has advised that objects have been located by a Royal Australian Air Force P3 Orion. And I can advise the House that HMAS Success is on scene and is attempting to locate and recover these objects," Mr Abbott told the Australian parliament.

Investigators could be closer to resolving "one of the great mysteries of our time", he added.

Speaking at a daily news briefing in Kuala Lumpur, Transport Minister Hishammuddin Hussein confirmed the missing airliner had been carrying wooden pallets, but said there was no connection yet to a reported Australian sighting of pallets floating in the search zone.