A plane window has been found by a Malaysian team on Reunion, along with other aircraft debris, a minister has said.
Malaysia's transport minister Liow Tiong Lai said he could not confirm the window belonged to MH370 but it comes after a flaperon found on the tiny island was formally identified as belonging to the missing Malaysia Airline jet.
Mr Liow said there were "many items" collected by the team, including some aluminium foil and seat cushions, and added: "I can only ascertain that it's plane debris."
The items have been sent to the French authorities for examination.
:: Can mystery of missing plane now be solved?
Malaysian Prime Minister Najib Razak earlier told reporters: "Today, 515 days since the plane disappeared, 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 from MH370.
"We now have physical evidence that, as I announced on 31 March last year, flight MH370 tragically ended in the Southern Indian Ocean. This is a remote, inhospitable and dangerous area.
"I would like to assure all those affected by this tragedy that the government of Malaysia is committed to do everything within our means to find out the truth of what happened."
The foreign ministry in China, where most of the passengers were from, said Mr Razak's declaration "confirmed the verdict on the Malaysia Airlines accident", and expressed "deep grief" for the passengers.
The announcement in Malaysia was met with anger and cynicism by Chinese relatives of some of the 239 passengers and crew who were on board when the flight disappeared on 8 March last year.
Many demanded that the search continue to find the bodies, with some refusing to believe that their relatives were dead.
The confusion was deepened after Australian deputy prime minister Warren Truss said: "Of course there is still some i's not dotted and t's not crossed. There is still a very small element of doubt."
Sara Weeks, the sister of New Zealander and MH370 passenger Paul Weeks, said: "Why the hell do you have one confirm and one not? Why not wait and get everybody on the same page so the families don't need to go through this turmoil?"
Zhang Meilin, whose daughter and son-in-law were on board, told Sky News: "If the plane crashed, the wreckage should be everywhere, there should be many pieces of wreckage in the sea, but where are the passengers?
"We believe our loved ones are still alive, we just believe that. So where are they?"
Australian PM Tony Abbott, whose country is co-ordinating the search, said it was vital for the safety of future air passengers to establish what happened.
He said the finding will not affect its sonar search of a 46,000-square-mile expanse of seabed more than 2,500 miles east of Reunion.
That search, which began in October, has covered almost half that area without finding any clues.
He later told reporters: "It suggests that for the first time we may be a little bit closer to solving this baffling mystery."
Jacquita Gonzales, wife of MH370 chief steward Patrick Gomes, said: "Although they found something, you know, it's not the end. They still need to find the whole plane and our spouses as well. We still want them back."
The airline said the discoveries are "a major breakthrough for us in resolving the disappearance of MH370".
They added: "We expect and hope that there would be more objects to be found which would be able to help resolve this mystery."