Australia says the search for possible objects from missing flight MH370 has been called off for the day. The Australian Maritime Safety Authority (AMSA) says the search will continue tomorrow.
Four aircraft were tasked by AMSA to the 23,000 square kilometre area, about 2,500 kilometres south-west of Perth.
It followed the discovery of objects that were spotted by a satellite a few days ago and could potentially be debris from the Boeing 777.
AMSA said they were a "reasonable size", with one around 24 metres in length and the other around five metres.
The aircraft involved in the search have been hampered rain, cloud had limited visibility. A first spotter flight by an Australian plane was unable to locate the objects and returned to base.
Flight MH370: Latest developments at a glance
The Australian Prime Minister Tony Abbott described the satellite sighting, around 1,550 miles (2,500km) southwest of Perth, or four hours by plane - as "credible" and a "potentially important development".
Malaysia's acting Transport Minister, Hishammuddin Hussein, called it a "credible lead".
The objects were spotted in the far south of the southern air corridor that investigators have been scouring over the last few days, along with a corridor further north.
Satellite images, which show the two objects floating on or just under the surface, were taken on March 16 but it has taken time to analyse the pictures, and the objects would have moved since then.
However, more satellite images are being taken of the area.
These images, which could be debris, were taken by an Australian satellite
Two Royal Australian Air Force Orion aircraft, a New Zealand Orion and a US Navy Poseidon aircraft are involved in the search.
"The task of locating these objects will be extremely difficult and it may turn out they are not related to search for MH370" Mr. Abbott warned.
"Pings" from a number of large objects are believed to have been picked up by a US spotter plane.
A Norwegian merchant ship has arrived in the vicinity and the Australian naval vessel HMAS Success, which is capable of retrieving any debris, is some days away. A British naval survey ship, HMS Echo, is also heading to the region.
The wider searches, including a northern corridor from northern Thailand to Kazakhstan, will go on until investigators are certain they have located the plane. Some 18 ships and 29 aircraft are taking part.
John Young, from the AMSA, cautioned the objects could be seaborne debris along a shipping route where containers can fall off cargo vessels, but the larger object is longer than a container.
Aircraft with lange range capabilities have been tasked to the area, but Australia has appealed for other nations to help too
The depth of the ocean in the latest search area is around 5,000 metres - twice as deep as where the Air France plane was found in the Atlantic Ocean.
The search for the missing Malaysian plane, which had 239 people on board, has been focused on the two corridors, one of which extends towards the southern reaches of the Indian Ocean.
Military planes from Australia, the US and New Zealand have been scouring the vast area, which was halved in size to 118,000 sq miles (305,000 sq km) on Wednesday.
There has been no trace of the aircraft since it vanished from radar a short distance into a flight from Kuala Lumpur to Beijing 12 days ago.
In Beijing, relatives of many of the 154 Chinese passengers waited anxiously for news from an AMSA news conference.
General Manager of AMSA's Emergency Response Division John Young and Air Commodore John McGarry from the Australian Department of Defence give an update earlier today.
Investigators believe two vital pieces of communication equipment were intentionally switched off and the aircraft deliberately diverted, potentially taking it thousands of miles off course.
Satellite data suggests the plane flew for at least seven hours after it was turned back across Malaysia towards the Strait of Malacca.
Investigators are considering a number of theories about what happened to the aircraft, including hijacking, sabotage and terrorism.
However, background checks on all foreign passengers apart from three from Ukraine and Russia have yielded "no information of significance", Mr. Hishammuddin said.
One theory that has gathered pace among aviation experts in recent days is that a fire in the cabin of flight MH370 may explain the mystery.
Dan Murphy is a Sky News reporter in Australia and he is at a Royal Australian Air Force base near Perth.
He told Newstalk Breakfast earlier that a naval vessel will be sent to the area - but even if something is found, it will be some time before it gets back to land.
