Governments involved in the search for the missing Malaysia Airlines Boeing 777-200, flight MH370, have resolved to continue the task – but the Australian co-ordinators of the exercise have declared they may soon need a new strategy.

Meanwhile, there have been no sightings of floating wreckage, and sheet metal flotsam washed up on the western Australian shore south of Perth has proven to be unconnected with the missing aircraft, according to the Joint Agency Co-ordination Centre. The visual search area is approximately 49,500km2, with its centre 1,580km (980 miles) northwest of Perth.

As of 24 April, a US Navy Bluefin-21 mini-submarine, scanning the ocean bed at a depth of 4,500m (14,800ft), had covered more than 90% of a designated search area northwest of Perth without finding any relevant debris. That was the area in which Australian Defence Vessel Ocean Shield detected “pings” on 8 April that could have come from the lost aircraft's flight data recorder or cockpit voice recorder. Since that time no more signals have been detected, probably because the batteries appeared to be beginning to run out of power when the vessel previously picked up the signals.

A fleet of 11 military aircraft and 11 ships from more than a dozen nations are allocated to the search at present. Australian Prime Minister Tony Abbott says his country is committed to the search, and that if the current underwater scan was unsuccessful, a new strategy would begin. The nation's defence minister David Johnston explains: "The next phase, I think, is that we step up with potentially a more powerful, more capable side-scan sonar to do deeper water."

MH370 disappeared on 8 March with 239 passengers and crew, while operating the Kuala Lumpur-Beijing route.