The plane crash which killed 150 people when a budget airliner slammed into a mountainside in the French Alps yesterday was probably an accident, according to its operator.

Lufthansa’s Germanwings confirmed flight 4U 9525 from Barcelona to Düsseldorf went down with 144 passengers – including 16 schoolchildren and two babies – and six crew.

One of the Airbus’s black box recorders has been found at the crash site, about 100 km (65 miles) north of the Riviera city of Nice, and will be examined immediately, France’s interior minister said.

In Washington, the White House said the crash did not appear to have been caused by a terrorist attack. Lufthansa said it was working on the assumption it was an accident, adding that any other theory would be speculation.

Aerial photographs showed smouldering wreckage and a piece of the fuselage with six windows strewn across the mountainside.

“We saw an aircraft that had literally been ripped apart, the bodies are in a state of destruction, there is not one intact piece of wing or fuselage,” Brice Robin, prosecutor for the city of Marseille, told Reuters after flying over the wreckage in a helicopter.

Germanwings believed 67 Germans were on the flight. Spain’s deputy prime minister said 45 passengers had Spanish names. One Belgian was also aboard. Also among the victims were 16 children and two teachers from the Joseph-Koenig-Gymnasium high school in the town of Haltern am See in northwest Germany, a spokeswoman said.

French police at the crash site about 2,000 metres above sea level said no one survived and it would take days to recover the bodies due to difficult terrain, snow and storms.

Police said search teams would stay overnight at altitude. “We are still searching. It’s unlikely any bodies will be airlifted until Wednesday,” regional police chief David Galtier told Reuters.