KUALA LUMPUR, Malaysia  -- Aircraft from Australia, New Zealand and the United States began to search the south Indian Ocean area Thursday for possible airplane debris spotted on satellite imagery, but they did not find anything amid poor weather and limited visibility.

The search for wreckage from missing Malaysia Airlines Flight 370 was called off at day's end, the Australian Maritime Safety Authority announced. It was expected to resume Friday morning.

Shortly after Australia announced it had detected two objects that could be from the missing jetliner, one of its air force planes scoured the area but returned to base in Perth without spotting anything.

Photos: Malaysia Airlines plane missing

"The weather conditions were such we were unable to see for very much of the flight today," Royal Australian Air Force Flight Lt. Chris Birrer told reporters, according to Reuters news service.

A U.S. Navy P-8A Poseidon later in the day reached the scene, about 1,500 miles southwest of the Australian city of Perth, but the Navy also reported that it did not detect debris from the Boeing 777 jetliner that disappeared on March 8.

By day's end, two more aircraft from Australia and New Zealand had joined the search, covering an area of nearly 9,000 square miles, the maritime authority said. A merchant ship had arrived in the area and another was en route, it said.

The satellite pictures were taken Sunday, the martime authority said, adding that because of the large volume of films and analysis required, the imagery showing the two objects, one measuring almost 80 feet, was not brought to the authority's attention until Thursday morning.

Malaysia's government on Thursday described the new sightings of possible airplane debris as "credible," even as officials sought to temper expectations and allay increasing anger from families of the passengers of that flight.

Asked why Australia's satellite detections were seen as more promising than earlier leads that proved false, Malaysia's acting transport minister, Hishammuddin Hussein, said the imagery was "corroborated to a certain extent by other satellites."

"We now have a credible lead," he said at a news conference here shortly after getting briefed by Australian officials.

Earlier in the day, Australian Prime Minister Tony Abbott told his country's parliament that "new and credible information has come to light in relation to the search ... in the south Indian Ocean."

The news of the possible debris, after nearly two weeks of false leads and many rumors, has raised hopes of a breakthrough in the mysterious disappearance of Malaysia Airlines Flight 370. The flight was on its way from Kuala Lumpur to Beijing with 239 passengers and crew aboard.

But for the families and relatives of those on board, the latest news brought a much more complex mix of emotions, which have swung from highs and lows as well as displaying deep frustration and anger over the handling of the investigation and information disclosures by the Malaysian government.

Hishammuddin, in the daily news conference, said the families of passengers would be briefed separately Thursday night. Although he noted that search efforts were being stepped up in the area of the satellite sightings, he also said he did not want to give them false hope.

Malaysia Airlines said that if the debris detections were confirmed to be from the missing Boeing 777, the families would be flown to Australia.

Hishammuddin also expressed regret at what happened Wednesday when three Chinese women representing families of the passengers protested in the Sama-Sama Hotel next to Kuala Lumpur's international airport where Malaysian officials have been meeting and briefing media. The women were pushed by security officers into a room amid jostling and shoving by media crews.

Hishammuddin said that the matter was being investigated and that high-level Malaysian officials were being sent to Beijing on Thursday evening to meet with and to provide updates to the families of passengers.

Chinese citizens accounted for about two-thirds of the passengers on the flight.

At the Lido Hotel in Beijing, where Chinese families of the passengers are gathered, people were glued to the television throughout the day, watching in a nearly dark conference room. It was numbingly quiet inside.