According to BBC, 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 Dusseldorf with 142 passengers and six crew on board.
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 and called for solidarity with the victims, adding that the area was very difficult to access.
He said he would be speaking shortly with German Chancellor Angela Merkel.
The plane issued a distress call at 10:47 (09:47 GMT), according to sources quoted by AFP news agency.
Search-and-rescue teams are headed to the crash site at Meolans-Revels, said regional council head Eric Ciotti.