A German A320 Airbus with 150 people on board has crashed in the Alps in southern France, reports the BBC.
The Germanwings flight was travelling non-stop from Barcelona in Spain to Duesseldorf in Germany. The cause of the crash is not yet known.
The Airbus came down in a remote mountainous region about 2,000m high, near the town of Digne in the Alps.
Rescuers are on their way to the area, which is near the popular ski resort of Pra Loup. The debris has been located.
French President Francois Hollande has described it as a tragedy. He said the circumstances of the crash made it seem unlikely there would be any survivors.
The BBC's transport correspondent Richard Westcott says it seems most likely mechanical failure was behind the crash.
The plane is one of the oldest A320s in operation. It entered service for the German airline in 1991.
Reports from Flightradar24, which tracks air traffic around the world, said the Airbus initially climbed to 38,000ft, before it started to descend. It says the signal from the plane was lost at 6,800ft.
According to sources quoted by AFP news agency, the plane issued a distress signal at 10:47 local time (09:47GMT) - about three-quarters of an hour after take-off.
Flightradar24 said the airbus was descending at a rate of about 3-4,000ft per minute, which, it said, was standard for an airport approach.