The German airliner crashed near a ski resort in the French Alps on Tuesday. It belonged to Germanwings, a low-budget carrier.
There were 144 passengers on board along with two pilots and four stewards.
French President Francois Hollande said it was likely all passengers and crew on the Airbus A320 had perished in the crash.
16 German school children were on board the plane, said a Spanish mayor.
At a press briefing, airline officials also said the plane went into an eight-minute descent before crashing.
The plane was travelling from the Spanish coastal city of Barcelona to the German city of Dusseldorf.
It went down in the Barcelonnette area in south-eastern France.
Germanwings is a low-cost affiliate of German airline Lufthansa.
The airline changed the colours of its logo on social media to black and gray to reflect the tragedy.
“If our fears are confirmed, this is a dark day for Lufthansa,” tweeted Lufthansa chief Carsten Spohr.
International