Malaysia said Thursday that paint-color and maintenance-record matches prove that a piece of wing found on the shore of an Indian Ocean island last week was part of the wreckage of Malaysian Airlines Flight 370, which vanished without trace last year in one of the biggest mysteries in aviation history.
Malaysian Transport Minister Liow Tiong Lai said that investigators on the French island of Réunion collected more aircraft debris, including a plane window but that there was no confirmation whether they also belong to the missing plane.
With the first trace of the plane now confirmed, Malaysia has asked the governments of neighboring Mauritius and Madagascar, where some experts believe MH370 debris could wash up, to help widen the search area, he told reporters.
On Wednesday, Malaysian Prime Minister Najib Razak confirmed that the wing part was from MH370's Boeing 777, which was bound for Beijing from Kuala Lumpur with 239 passengers and crew members on board when it went missing.
Exactly what happened to the plane remains unknown, and Najib's announcement did not appear to provide resolution for the families of those on board, most of whom were Chinese.
The fragment of wing, a flaperon, was flown to mainland France after being found last week covered in barnacles on a beach on Réunion. Despite the Malaysian confirmation, prosecutors in France stopped short of declaring they were certain, saying only that there was a "very strong presumption" that the part came from the missing plane.
Paris prosecutor Serge Mackowiak said this presumption was based on technical data supplied by the manufacturer and the airline but gave no indication that experts discovered a serial number or unique markings that would put the link beyond doubt.
Mackowiak told reporters in Paris that more analysis would be carried out on Thursday and that a fragment of luggage also found in Réunion would be examined by French police.
"We appreciate the French team and their support and respect their decision to continue with the verification," Liow said, adding that Malaysian experts were convinced the flaperon was from MH370 because a seal on the part matched a maintenance record and the paint was the same color.
The Australian government, which leads the seabed search for wreckage west of Australia, is also less certain than Malaysia, saying in a statement that "based on high probability, it is MH370."
Australian officials, who said Thursday that the ocean floor search off its coast would continue despite the effort turning up nothing over the last 10 months, are withholding criticism of Najib's announcement, with Australian Transport Minister Warren Truss saying Malaysia, as the government in charge of the investigation, had the right to make that call.
"We respect the view that they believe they have sufficient evidence to make a categorical statement of that nature," Truss told reporters. "The French inquiry, of course, has not been quite so conclusive."
Meanwhile, a group of families from China said French investigators and Boeing must also say definitively the wing piece was from the plane.
"We are not living in denial … but we owe it to our loved ones not to declare them lost without 100 percent certainty," the families said on their microblog.
Families in Malaysia and Australia expressed similar sentiments. China's Foreign Ministry urged Malaysia to keep investigating and to "safeguard the legitimate rights and interests" of the relatives.
Investigators looking at the wing flap are likely to start by putting thin slices of metal under a high-powered microscope to find clues in its crystal structure about how it deformed on impact, said Hans Weber, the president of TECOP International, an aerospace technology consulting firm.
Investigators would probably then clean it and "do a full physical examination, using ultrasonic analysis before they open it up to see if there's any internal damage," he said. "That might take quite a while — a month or months."
Al Jazeera and wire services