An Airbus A320 airliner has crashed in the French Alps between Barcelonnette and Digne, French aviation officials and police have said.
The jet belongs to the German airline Germanwings, a subsidiary of Lufthansa.
The plane, flight 4U 9525, had been en route from Barcelona to Duesseldorf with 144 passengers and six crew.
French President Francois Hollande said: “The conditions of the accident, which have not yet been clarified, lead us to think there are no survivors.”
Mr Hollande said the crash was a tragedy, adding that the area was very difficult to access.
Mr Hollande later called German Chancellor Angela Merkel to express his sympathy, the French presidency said.
Spain’s King Felipe, on a state visit to France, thanked the French government for its help and said he was cancelling the rest of his visit.
The plane issued a distress call at 10:47 (09:47 GMT), the French interior ministry said, although details have not been released.
Search-and-rescue teams are headed to the crash site at Meolans-Revels, said regional council head Eric Ciotti.