Thunderstorms and gale-force winds grounded the international air search for wreckage from Flight MH370 on Thursday, frustrating the effort again as Thailand reported a satellite sighting of hundreds of floating objects.

The Thai report was the second in two days suggesting a possible debris field from the crashed jet in the stormy southern Indian Ocean.

But a major air and sea search has frustratingly failed so far to secure any wreckage confirmed to have come from the Malaysia Airlines passenger plane which went missing on March 8 with 239 people on board.

Planes and ships have faced fierce winds and sometimes mountainous seas as they hunt for hard evidence that the plane crashed, as Malaysia has concluded.

On Tuesday the Australian Maritime Safety Authority (AMSA) called off both the air and sea search.

The agency on Thursday suspended the air search because of worsening weather after it had got under way, but said ships would try to continue.

"Bad weather expected for next 24 hours," it tweeted.

Thailand's Geo-Informatics and Space Technology Development Agency said it had satellite images taken on Monday of 300 objects, ranging in size from two to 15 metres (6.5 to 50 feet).

It said they were scattered over an area about 2,700 kilometres (1,680 miles) southwest of Perth, but could not confirm they were plane debris.

The agency said the objects were spotted about 200 kilometres away from an area where French satellite images earlier showed objects.

Malaysia said late Wednesday that the French images taken Sunday showed 122 floating objects including some as long as 23 metres.

The Boeing 777 is presumed to have crashed after mysteriously diverting from its Kuala Lumpur-Beijing path and apparently flying for hours in the opposite direction.

Malaysia believes the plane was deliberately redirected by someone on board, but nothing else is known.

A total of nine planes from Australia, China, Japan and New Zealand took part in Thursday's aborted search, the Malaysian transport ministry said, along with five Chinese ships and an Australian warship.

- Clock ticks on black box -

The search suspensions caused mounting concern as the clock ticks on the signal emitted by the plane's "black box" of flight data.

The data is considered vital to unravelling the flight's mystery but the signal, aimed at guiding searchers to the device on the seabed, will expire in under two weeks.

The drama is playing out in a wild expanse of ocean described by Australian Prime Minister Tony Abbott as "about as close to nowhere as it's possible to be".

Seeking closure, anguished families of those aboard are desperately awaiting hard evidence, which might also provide some answers to one of aviation's greatest mysteries.

Malaysia's government said Monday that satellite data indicated the plane plunged into the sea, possibly after running out of fuel.

MH370 relatives endured more than a fortnight of agonising uncertainty before the announcement, and several refuse to abandon hope until debris is found.

Two-thirds of the passengers were from China. Relatives there have criticised Malaysia in acid terms, accusing the government and airline of a cover-up and of botching the response.

- 'Appalling' handling -

The sister of New Zealand victim Paul Weeks lashed out Thursday.

"The whole situation has been handled appallingly, incredibly insensitively," Sara Weeks told Radio Live in New Zealand.

"The Malaysian government, the airline, it's just all been incredibly poor."

Scores of Chinese relatives protested outside Malaysia's embassy in Beijing on Tuesday, and a day later Premier Li Keqiang urged Malaysia to involve "more Chinese experts" in the investigation.

A relatives' briefing in Beijing began Thursday with images of children's paintings and candle arrangements calling for the return of Flight MH370 being shown on a screen.

Security was tighter, with a coachload of uniformed police arriving shortly before the briefing began.

Malaysia's ambassador to China and airline officials have endured a stream of abuse from relatives in Beijing.

Malaysian officials have urged the Chinese government to "clarify the actual situation" surrounding the plane to the relatives and the general public, the Malaysian transport ministry said in a statement.

It was said the request was made through China's ambassador to Malaysia.

Scenarios about the plane's fate include a hijacking, pilot sabotage or a crisis that incapacitated the crew and left the plane to fly on auto-pilot until it ran out of fuel.

The focus has been on the pilot, Captain Zaharie Ahmad Shah, with the FBI Wednesday saying it was close to completing an analysis of data from a flight simulator taken from his home.

Malaysian authorities had sought FBI help to recover files deleted from the hard drive.

So far, no information implicating the captain or anyone else has emerged.

His youngest son Ahmad Seth has dismissed speculation his father may have crashed the plane intentionally, a report said Thursday.

"I've read everything online. But I've ignored all the speculation. I know my father better," the son was quoted by the New Straits Times as saying.

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