They are the most tantalising clues yet: 122 objects spotted by satellite, floating in the turbulent Indian Ocean where officials believe the missing Malaysian jetliner went down.
But bad weather, the passage of time and the sheer remoteness of their location kept answers out of the searchers' grasp.
Nineteen days into the mystery of Flight 370, the discovery of the objects that ranged in size from 0.9m to 75m, offered "the most credible lead that we have," a top Malaysian official said yesterday.
Watch: Possible debris field found
With clouds briefly thinning in a stretch of ocean known for dangerous weather, aircraft and ships from six countries combed the waters far southwest of the Australian coast. Crews saw only three objects, one of them blue and two others that appeared to be rope.
But search planes could not relocate them or find the 122 pieces seen by a French satellite. Limited by fuel and distance, they turned back for the night.
That echoed the frustration of earlier sweeps that failed to zero in on three objects seen by satellites in recent days. Forecasters warned that the weather was likely to deteriorate again Thursday, possibly jeopardising the search for the Malaysia Airlines Boeing 777 that vanished early March 8 en route from Kuala Lumpur to Beijing.
The latest satellite images, captured Sunday and relayed by French-based Airbus Defense and Space, are the first to suggest a debris field from the plane, rather than just isolated objects. The items were spotted in roughly the same area as other objects previously seen by Australian and Chinese satellites.
Clouds obscured the latest satellite images, but dozens of objects could be seen in the gaps. At a news conference in Kuala Lumpur, Hishammuddin said some of them "appeared to be bright, possibly indicating solid materials."
Australian officials did not say whether they received the French imagery in time for search planes out at sea to look for the objects, and did not return repeated phone messages seeking further comment. None of the three objects spotted by searchers Wednesday "were considered to be distinctive to MH370 or relevant to the satellite imagery," Australian Maritime Safety Authority officials said.
If the objects are confirmed to be from the flight, "then we can move on to deep sea surveillance search and rescue, hopefully, hoping against hope," Hishammuddin said.
But experts cautioned that the area's frequent high seas and bad weather and its distance from land complicated an already-trying search.
A representative of relatives of Chinese passengers on board Malaysia Airlines Flight 370, center, speaks to journalists. Photo / AP
"This is a really rough piece of ocean, which is going to be a terrific issue," said Kerry Sieh, director of the Earth Observatory of Singapore. "I worry that people carrying out the rescue mission are going to get into trouble."
"We're facing an extremely challenging environment, and 'unprecedented' is an overused word that in this case applies," said John Cox, a former airline pilot and accident investigator who is now president and CEO of Safety Operating Systems, an aviation safety consultancy.
The search resumed Wednesday after fierce winds and high waves forced crews to take a break Tuesday. Twelve planes and five ships from the U.S., China, Japan, South Korea, Australia and New Zealand were participating, hoping to find even a single piece of the jet that could offer tangible evidence of a crash and provide clues to the rest of the wreckage.
Malaysia said Monday that an analysis of the final known satellite signals from the plane showed that it had gone down in the sea, with no survivors.
That data greatly reduced the search zone to an area estimated at 1.6 million square kilometers (622,000 square miles), about the size of Alaska. Wednesday's search focused on an 80,000-square-kilometer (31,000-square-mile) swath of ocean about 2,000 kilometers (1,240 miles) southwest of Perth.
"We're throwing everything we have at this search," Australian Prime Minister Tony Abbott told Nine Network television.
"This is about the most inaccessible spot imaginable. It's thousands of kilometers from anywhere," he later told Seven Network television. "We will do what we can to solve this riddle."
Frustration at grieving relatives
Malaysian Defense Minister Hishammuddin Hussein expressed exasperation with the anger rising among missing passengers' relatives in China, who berated Malaysian government and airline officials earlier in the day in Beijing.
About two-thirds of the missing are Chinese, but Hishammuddin pointedly said that Chinese families "must also understand that we in Malaysia also lost our loved ones" as did "so many other nations."
Malaysia has been criticised over its handling of the search, though it is one of the most perplexing mysteries in aviation history. Much of the most strident criticism has come from relatives of the 153 Chinese missing, some of whom expressed outrage that Malaysia essentially declared their loved ones dead without recovering a single piece of wreckage.
At a hotel banquet room in Beijing on Wednesday, a delegation of Malaysian government and airline officials explained what they knew to relatives of those lost. They were met with skepticism and even ridicule by some of the roughly 100 people in audience, who questioned some of the report's findings, including how investigators could have concluded the direction and speed of the plane. One man later said he wanted to pummel everyone in the Malaysian delegation.
"Time will heal emotions that are running high. We fully understand," Hishammuddin said in Kuala Lumpur.
"For the Chinese families, they must also understand that we in Malaysia also lost our loved ones. There are so many other nations that have lost their loved ones," Hishammuddin said. "I have seen some images coming from Australia, very rational. (They) understand that this is a global effort. Not blaming directly on Malaysia, because we are coordinating something that is unprecedented."
But one of the main complaints from families - mixed messages from Malaysia - continued Wednesday. Two days after Malaysian Prime Minister Najib Razak said there were no survivors, Hishammuddin allowed for the possibility that some people aboard the plane might still be alive.
"If (the debris) is confirmed to be from MH370, then we can move on to deep sea surveillance search and rescue, hopefully, hoping against hope," he said.
China dispatched a special envoy to Kuala Lumpur, Vice Foreign Minister Zhang Yesui, who met Najib and other top officials Wednesday, the official Xinhua News Agency reported.
China, which now has Chinese warships and an icebreaker in the search zone, has been intent on supporting the interests of the Chinese relatives of passengers, backing their demands for detailed information on how Malaysia concluded the jet went down - details Hishamuddin said Malaysia handed over on Wednesday.
China's support for families is the likely reason why authorities there - normally extremely wary of any spontaneous demonstrations that could undermine social stability - permitted a rare protest Tuesday outside the Malaysian Embassy in Beijing, during which relatives chanted slogans, threw water bottles and briefly tussled with police who kept them separated from a swarm of journalists.
Hunt for elusive black box
The search for the wreckage and the plane's flight data and cockpit voice recorders will be a major challenge. It took two years to find the black box from Air France Flight 447, which went down in the Atlantic Ocean on a flight from Rio de Janeiro to Paris in 2009, and searchers knew within days where that crash site was.
Wednesday's search focused on an 80,000 square kilometer (31,000 square mile) swath of ocean about 2,000 kilometers (1,240 miles) southwest of Perth.
There is a race to find Flight 370's black boxes, whose battery-powered "pinger" could stop sending signals within two weeks.
On Wednesday, the Australian Maritime Safety Authority, which is coordinating the southern search operation on Malaysia's behalf, said a US Towed Pinger Locator arrived in Perth along with a Bluefin-21 underwater drone. The equipment will be fitted to the Australian naval ship the Ocean Shield, but AMSA could not say when they would be deployed.
Kerry Sieh, the director of the Earth Observatory of Singapore, said the seafloor in the search area is relatively flat, with dips and crevices similar to the part of the Atlantic Ocean where the Air France wreckage was found.
He believes any large pieces of the plane would likely stay put once they have completely sunk. But recovering any part of the plane will be tough because of ocean depths in the search area, which are mostly 3,000 to 4,500 meters (10,000 to 15,000 feet).
Aviation expert Geoffrey Thomas, publisher of Airlineratings.com, called the search "the most complex, the most difficult in aviation history."
"The weather in this part of the world is far more difficult than that experienced in the search for (Air France) 447."
He said huge swells were common, particularly during the southern hemisphere's upcoming winter. "There's a real urgency to find something as quickly as possible because through the winter months, they'll probably have to suspend the search."
Australia's Bureau of Meteorology warned that the weather was expected to deteriorate again Thursday, with thunderstorms, low clouds and strong winds on the way.