KUALA LUMPUR, Malaysia (AP) -- Malaysia's transport minister said Thursday that a maintenance seal and other details prove that a wing part found on an Indian Ocean island belongs to missing Malaysia Airlines Flight 370, a claim the prime minister made hours earlier but that other countries involved in the investigation have shied from making.
Transport Minister Liow Tiong Lai said a maintenance seal on the flaperon matches the airline's records, though he didn't elaborate.
"From our first observation, the color tone and all maintenance records that we have, we know. Our records show that it's the same as MH370," Liow said. He said there are "many other technical details that I do not have to reveal" but that confirm the part is from Flight 370.
Malaysian Prime Minister Najib Razak announced early Thursday morning that the part, known as a flaperon, did indeed come from the doomed aircraft, but authorities in France, the U.S. and Australia have stopped short of full confirmation.
The conflicting comments infuriated many families of those on board the plane, who have waited more than 500 days for concrete clues into the fates of their loved ones. Dai Shuqin, the sister of one of the passengers, was among about a dozen Chinese relatives who held a demonstration outside Malaysia Airlines' offices in Beijing.
"France is being cautious about it, but Malaysia is desperate to put an end to this case and run away from all responsibilities," she said.
Liow said differences with other countries amounted to "a choice of words."
"They want to continue with additional tests. We respect their decision," Liow said of the French.
Liow also said more apparent plane debris has been found on Reunion Island and sent to local authorities for French investigators to examine. He said a Malaysian team found the objects, including a window and some aluminum foil, but the minister's press secretary later it was "window material" rather than a window that was recovered.
"I can only ascertain that it's plane debris," Liow said. "I cannot confirm that it's from MH370."
The disappearance of the Boeing 777 jetliner while on a flight from Kuala Lumpur to Beijing on March 8, 2014, has been one of the biggest mysteries in aviation history. Officials believe it crashed in the southern Indian Ocean, killing all 239 people on board, but the wreckage and the cause remain elusive.
"It is with a very heavy heart that I must tell you that an international team of experts has conclusively confirmed that the aircraft debris found on Reunion Island is indeed MH370," Najib told reporters. The French territory is thousands of kilometers (miles) west of the area being searched for wreckage from the flight.
But at a news conference in Paris, Deputy Prosecutor Serge Mackowiak declined to confirm that the debris belonged to Flight 370, though he said there were strong indications that it did.
"The very strong conjectures are to be confirmed by complementary analysis that will begin tomorrow morning," Mackowiak said. "The experts are conducting their work as fast as they can in order to give complete and reliable information as quickly as possible."
The caution was typical of how France carries out air crash investigations. The French agency that usually handles such probes, known as the BEA, can take months if not years to lay out exhaustive conclusions in reports that last hundreds of pages. During the inquiries, they only rarely offer interim assessments and even more rarely comment.
The Australian government, which leads the seabed search for wreckage west of Australia, was also less certain than Malaysia, saying only that "based on high probability, it is MH370."
Publicly, Australian officials withheld criticism of Najib's announcement, with Australian Transport Minister Warren Truss saying Australia respected Malaysia's right to make that call, given it is the government in charge of the investigation.
"Of course there is still some i's not dotted and t's not crossed. There is still a very small element of doubt," Truss said.
Privately, however, there were questions about why Najib had moved forward with the statement before all countries had agreed. An Australian government official, speaking on condition of anonymity because he wasn't authorized to comment publicly, said Malaysia wasn't supposed to make the announcement, and had gone out on its own making a conclusive statement before getting the evidence to back it up.
Many families of those on board, who have waited nearly 17 months for tangible evidence, were fed up with the mixed messages.
"Why the hell do you have one confirm and one not?" said Sara Weeks, the sister of New Zealander Paul Weeks, who was on board. "Why not wait and get everybody on the same page so the families don't need to go through this turmoil?"
Ross Tapsell, a Malaysia expert at the Australian National University, said he suspects Najib was trying to distract Malaysians from a corruption scandal. On Monday, Malaysia's anti-corruption agency said that $700 million in Najib's personal bank accounts came from donations, not from a debt-ridden state investment fund.
"He's under so much political pressure at the moment," Tapsell said. "I presume if he can try to move the conversation back to the MH370 stuff, it's in his interests to do so."
Najib would also want to stamp his authority on the search, which Malaysia oversees, Tapsell said, rather than allow France to dominate attention through its leading role in examining the wing fragment.
A U.S. official familiar with the investigation said the flaperon clearly is from a Boeing 777. However, a team of experts in France examining the part hadn't yet been able to find anything linking it specifically to the missing plane, the official said, speaking on condition of anonymity because there was no authorization to talk publicly about the case.
With no other 777s or flaperons known to be missing, it makes sense that the part comes from Flight 370, but the U.S. and Boeing team members are merely trying "to be precise," the official said.
Australia, which sent an official to France to help examine the flaperon, has said the find will not affect its sonar search of a 120,000-square kilometer (46,000-square mile) expanse of seabed more than 4,000 kilometers (2,500 miles) east of Reunion Island.
That search, which began in October, has covered almost half that area without finding any clues.
Australian Prime Minister Tony Abbott told Melbourne Radio 3AW that the apparent discovery of Flight 370 wreckage "does seem very consistent with the search pattern that we've been using for the last few months."
"Let's hope we can turn something up," he said.
Intact and encrusted with barnacles, the flaperon was found on a beach and sent to France for scrutiny by the BEA and members from its Malaysian and Australian counterparts.
Analysts say investigators will examine the metal with high-powered microscopes to gain insight into what caused the plane to go down. But it won't fully solve the mystery of why the plane disappeared, nor will it help pinpoint where the plane crashed.
It is not known why Flight 370 — less than an hour into its journey — turned back from its original flight path and headed in an opposite direction before turning left and flying south over the Indian Ocean for hours.
A six-week air and sea search covering 4.6 million square kilometers (1.8 million square miles) of the southern Indian Ocean surface last year failed to find any trace of the jetliner. The Reunion Island debris would support the working theory that the jet went down in the Indian Ocean and the debris was carried by the current.
Malaysian officials have said the plane's movements were consistent with deliberate actions by someone on the plane, suggesting someone in the cockpit intentionally flew the aircraft off course.
Since last year, Australian officials who are leading the search effort have operated on the theory that the plane flew on autopilot for hours before running out of fuel and crashing into the ocean. Investigators settled on that scenario after analyzing data exchanged between the plane and a satellite, which showed the jetliner took a straight path across the ocean.