Planes and a ship scrambled Sunday to find a pallet and other debris in a remote patch of the southern Indian Ocean to determine whether the objects were from the Malaysia Airlines jet that has been missing for more than two weeks.
The pallet was spotted by a search plane Saturday, but has not been closely examined. Wooden pallets are commonly used in shipping, but can also be used on planes.
It is the latest in a series of clues experts and searchers are trying to run down to solve the mystery of what happened to Flight 370 when it disappeared on March 8 with 239 people on board.
Mike Barton, chief of Australian Maritime Safety Authority's rescue coordination center, told reporters in Canberra, Australia, that the wooden pallet spotted by a civilian search aircraft was surrounded by several other nondescript objects, including what appeared to be strapping belts of different colors and lengths.
It was not immediately known if any pallets were used on Flight 370.
A New Zealand Orion P3 plane tried to find it, but failed, Barton said.
"So, we've gone back to that area again today to try and re-find it," he said. A merchant ship also was sent to try to identify the material.
"We went to some of the expert airlines and the use of wooden pallets is quite common in the industry," Barton said. "They're usually packed into another container which is loaded in the belly of the aircraft. ... It's a possible lead, but we will need to be very certain that this is a pallet because pallets are used in the shipping industry as well," he said.
Search planes - eight of them were in the air Sunday - are scouring an area about 2,500 kilometers (1,550 miles) southwest of Perth, Australia. Satellite images, the most recent released by China on Saturday, have showed large objects floating in the area that experts want to check to see if they came from the jetliner.
Air and sea searches since Thursday have not produced any results.
John Young, manager of the Australian Maritime Safety Authority's emergency response division, said Sunday's search was mainly relying on human eyes.
"Today is really a visual search again, and visual searches take some time. They can be difficult," he said.
Barton said while the weather was not as good at the start of the day with sea fog and low cloud, it was clearing up later Sunday.
Despite the frustrating lack of answers, Australian Prime Minister Tony Abbott was upbeat.
"Obviously we have now had a number of very credible leads and there is increasing hope - no more than hope, no more than hope - that we might be on the road to discovering what did happen to this ill-fated aircraft," Abbott told reporters in Papua New Guinea.
The Australian Maritime Safety Authority said it had refined the search based on the latest clue from the Chinese satellite showing an object that appeared to be 22 meters (72 feet) by 13 meters (43 feet). It said the object's position also fell within Saturday's search area but it had not been sighted.
Sunday's search has been split into two areas within the same proximity covering 59,000 square kilometers. These areas have been determined by drift modelling, the AMSA said.
Malaysian Defense Minister Hishammuddin Hussein put a message on his Twitter account Sunday asking those in churches around the country to offer a "prayer please" for the passengers and crew on Fight 370.
More than 300 Malaysian cycling enthusiasts rode their bikes to the Kuala Lumpur airport to remember the people onboard the jet. The cyclists decorated the bikes with small Malaysian flags and stickers that read "Pray for MH370."
The latest satellite image is another clue in the baffling search for Flight 370, which dropped off air traffic control screens March 8 over the Gulf of Thailand with 239 people on board.
"China hopes that these data will be helpful for searching and rescuing efforts," Chinese Foreign Ministry spokesman Hong Lei said in a statement.
The missing plane, which had been bound for Beijing, carried 153 Chinese passengers.
After about a week of confusion, Malaysian authorities said pings sent by the Boeing 777-200 for several hours after it disappeared indicated that the plane ended up in one of two huge arcs: a northern corridor stretching from Malaysia to Central Asia, or a southern corridor that stretches toward Antarctica.
The discovery of the initial two objects by a satellite led several countries to send planes and ships to a stretch of the ocean southwest of Australia.
Two military planes from China have arrived in Perth, and the AMSA said they would join the search on Monday. They join Australian, New Zealand and US aircraft. Japanese planes are also expected soon.
Because the search area is a four-hour flight from land, some of the planes can search for about only two hours before they must fly back. Others may be able to stay for up to five hours before heading back to the base.
Malaysian authorities have not ruled out any possible explanation for what happened to the jet, but have said the evidence so far suggests it was deliberately turned back across Malaysia to the Strait of Malacca, with its communications systems disabled. They are unsure what happened next.
Police are considering the possibilities of hijacking, sabotage, terrorism or issues related to the mental health of the pilots or anyone else on board.