A search for possible debris from missing Malaysian airliner MH370 has been concluded for the day by Australian authorities. The Australian Maritime Safety Authority (AMSA) says the search will resume tomorrow.

The operation involved five aircraft, including three RAAF Orions, and a US Navy P8 Poseidon which are scouring a remote area of 8,800 square miles (23,000 sq km).

An Australian P3 Orion search plane had already arrived back at base in Perth after failing to find any evidence of debris from the missing aircraft.

Today's search activities for #MH370 have now concluded. The search will resume tomorrow. http://t.co/pdSSisZuZ1

— AMSA News (@AMSA_News) March 21, 2014

But Australian Deputy Prime Minister Warren Truss says nothing of significance had been spotted in plane search so far. He also said the objects spotted on satellite images in the remote southern Indian Ocean may have sunk.

"Something that was floating on the sea that long ago may no longer be floating," he told reporters in Perth.

"It may have slipped to the bottom".

Meanwhile, the Australian Prime Minister Tony Abbott said the country was doing everything it could to find the suspected debris and to keep the families of the passengers informed of the progress.

"We owe it to the families, the friends and the loved ones of the nearly 240 people on board flight MH370 to do everything we can to resolve what is as yet an extraordinary riddle," he said at a news conference.

"Because of the understandable state of anxiety they're in, we also owe it to them to give them information as soon as we get it to hand. We have five aircraft searching the area. We're looking for a visual that was picked up on satellite imagery and as soon as we have additional information we'll make it available".

General Manager of AMSA's Emergency Response Division John Young gave given an update on the search earlier.

A Norwegian merchant ship - the first vessel to reach the vicinity - has been using searchlights through the night to try to locate the objects.

They were spotted by a satellite last Sunday and could potentially be debris from flight MH370, one of which is thought to be 24 metres in length and the other about five metres.

Searches yesterday were hampered by strong winds, cloud and rain.

The sightings have been deemed "credible" and a "potentially important development" by authorities - as the search for the passenger plane enters its 13th day.

Australian naval vessel HMAS Success, which is capable of retrieving debris, is also en route to the search area but is some days away.

A British naval survey ship, HMS Echo, is also heading to the region.

There has been no trace of the aircraft since it vanished from radar a short distance into a flight from Kuala Lumpur to Beijing on March 8th.

Wider searches, including of a northern corridor from northern Thailand to Kazakhstan, are set to continue until investigators are certain they have located the plane. Some 18 ships and 29 aircraft are taking part.

Those areas were targeted after faint electronic "pings" picked up by one commercial satellite suggested flight MH370 flew on for at least six hours after it disappeared from air traffic control screens.

This new search area is too vast for many aircrafts to get to without needing to refuel.

Oceanographer Dr. Simon Boxall says that even long range planes will have very little time in the search zone before needing to return to base.

Willie Walsh, chief executive of the International Airlines Group, said he was baffled by the disappearance of the aircraft.

"My deepest sympathies to everybody associated with this, it must be truly awful for the families and friends of the passengers and crew" he said.

"I'm baffled; I must have heard 20, 30, maybe even 40 theories on what has happened and quite honestly, we just don't know. I've been in this industry 35 years and I've never seen anything like this. I'm confident that with the technology today and the fact accident investigation has progressed significantly, we will ultimately find out" he added.

Cameron Price is a Sky News journalist at the Perth RAAF airbase in Western Australia. He spoke to Newstalk Breakfast earlier.