The large objects, which Australian officials said were spotted by satellite four days ago in one of the remotest parts of the globe, are the most promising lead in days as searchers scour a vast area for the lost plane with 239 people on board.
Officials cautioned it could take several days to confirm if they were parts of the Malaysia Airlines Boeing 777, and Malaysia's government said the search would continue elsewhere despite the possible sighting in the southern Indian Ocean.
The area where the objects were spotted is around 2,500 km (1,500 miles) southwest of Perth in western Australia.
"Yesterday I said that we wanted to reduce the area of the search. We now have a credible lead," Malaysian Transport Minister Hishammuddin Hussein told reporters in Kuala Lumpur.
"There remains much work to be done to deploy the assets. This work will continue overnight."
Hishammuddin said the information on the objects received from Australia had been "corroborated to a certain extent" by other satellites, making it more credible than previous leads.
The larger of the objects measured up to 24 metres (79 ft), long and appeared to be floating in water several thousand metres deep, Australian officials said. The second object was about five metres (16 feet) long. Arrows on the images pointed to two indistinct objects apparently bobbing in the water.
"It's credible enough to divert the research to this area on the basis it provides a promising lead to what might be wreckage from the debris field," Royal Australian Air Force Air Commodore John McGarry told a news conference in Canberra.
No confirmed wreckage from Flight MH370 has been found since it vanished from air traffic control screens off Malaysia's east coast early on March 8, less than an hour after taking off from Kuala Lumpur for Beijing.
Another official in Malaysia said investigators were "hopeful but cautious" about the Australian discovery.
The satellite images, provided by U.S. company DigitalGlobe, are stamped with a record date of March 16, meaning that the possible debris could by now have drifted far from the original site.
Australian officials said an aircraft had dropped a series of marker buoys in the area, which will provide information about currents to assist in calculating the latest location.
The captain of the first Australian air force AP-3C Orion plane to return from the search area described the weather conditions as "extremely bad" with rough seas and high winds, and said there was no sign of any objects.
"The weather conditions were such that we were unable to see for very much of the flight today but the other aircraft that are searching, they may have better conditions," Royal Australian Air Force Flight Lieutenant Chris Birrer told reporters.
At least one aircraft, a Royal New Zealand Air Force Orion, was still in the search area, while other aircraft including a U.S. Navy P-8 Poseidon were returning to Perth, according to the Australian Maritime Safety Authority (AMSA). (Largest 'object' sighted in MH370 search is 24 metres: authorities)
A Norwegian car carrier diverted from its journey from Madagascar to Melbourne to help with the search and had arrived in the area, the ship's owner said. A Royal Australian Navy ship equipped to recover any objects was also en route, but was still "some days away", Young said.
The fate of Flight MH370 has been baffling aviation experts for nearly two weeks.
Investigators believe that someone with detailed knowledge of both the Boeing 777-200ER and commercial aviation navigation switched off the plane's communications systems before diverting it thousands of miles off its scheduled course. (Plane debris would be a modest clue, experts say)
Exhaustive background checks of the passengers and crew aboard have not yielded anything that might explain why. (Seven leading theories on disappearance of Flight 370)
The huge potential breakthrough in an investigation that had appeared to be running out of leads was revealed by Australian Prime Minister Tony Abbott, who told parliament the objects had been located with satellite imagery.
"New and credible information has come to light in relation to the search for Malaysia Airlines Flight MH370 in the southern Indian Ocean," Abbott said.
He added that he had already spoken with his Malaysian counterpart, Najib Razak, and cautioned that the objects had yet to be identified.
"The task of locating these objects will be extremely difficult and it may turn out they are not related to the search for MH370," Abbott said.
The dimensions of the objects given are consistent with at least one of them possibly being the major part of a 777-200ER wing, which is around 27 metres (89 feet) long, though Australian officials cautioned the first images were indistinct.
The relatively large size of the objects would also suggest that, if they do come from the missing aircraft, it was intact when it went into the water.
University of Western Australia Professor of Oceanography Charitha Pattiaratchi said that, based on currents in the area, if the debris is from the plane it probably would have entered the water around 300-400 km (180-250 miles) to the west.
The search area covered an ocean ridge known as Naturalist Plateau, a large sea shelf about 3,500 metres (9,800 feet) deep, Pattiaratchi said. The plateau is about 250 km (150 miles) wide by 400 km (250 miles) long, and the area around it is close to 5,000 metres (16,400 feet) deep.
"Whichever way you go, it's deep," he said.