AIR disaster experts have begun the grim task of recovering the bodies of 150 passengers and crew from a passenger plane which came down in the French Alps.

Sixteen schoolchildren and two teachers are known to be among the victims of the disaster, which happened yesterday lunchtime.

The pupils, from Joseph Konig school in Haltern am See in western Germany, were flying home after a week-long exchange with students at a school near Barcelona.

Two babies are also thought to have been on the Airbus A320 operated by low-fare carrier Germanwings, which was flying from Barcelona to Dusseldorf.

There were no survivors from the 144 passengers and six crew after the plane went into an eight-minute descent before crashing near Digne.

Prime Minister David Cameron and Deputy Prime Minister Nick Clegg said their thoughts were with the families of the passengers.

The victims are believed to have included a total of 67 Germans, including an opera singer, many Spaniards, business travellers en route to a trade fair in Cologne and one person from the Netherlands.

The German students and their teachers spent a week in Llinars del Valles and were seen off at the town's train station for their early morning trip to the airport by their Spanish host families

German and Spanish students from the two towns have been taking part in exchanges for at least 15 years, and the Spanish students had spent time in Germany in December.

Pere Grive, the deputy mayor of Llinars del Valles, said: "We are completely shattered and the students are also devastated," Mr Grive said.

In Haltern, the high school was going to be kept open but no classes are planned.

Bodo Klimpel, Mayor of Haltern, spoke of the shock and disbelief that had greeted news of the crash, saying: "This is pretty much the worst thing you can imagine."

"You can feel a state of shock everywhere. There will be an opportunity for the students to talk about the terrible event."

The town of 38,000 lies about 80km (50 miles) north east of the plane's destination.

Some people hugged and cried in front of the Joseph Koenig High School, where the 10th graders had studied, and put candles on its steps.

In Duesseldorf, the Deutsche Oper am Rhein opera house said bass baritone Oleg Bryjak was among the victims. He was returning from Barcelona, where he had sung Alberich in Richard Wagner's Siegfried at the Gran Teatre del Liceu.

"We have lost a great performer and a great person in Oleg Bryjak. We are stunned," director Christoph Meyer said.

In Spain, authorities were still trying to determine how many of their citizens were on board.

Business travellers included Carles Milla, the managing director for a small Spanish food machinery company, his office said, adding that he had been on his way to a food technology fair in Cologne.

Two employees of Barcelona's trade fair organisation were also on the flight.

German chancellor Angela Merkel and various French ministers travelled to the crash site in a remote area.

Those on board the first helicopter to land near the site confirmed there were no survivors, with witnesses describing how the plane had disintegrated with no piece of wreckage bigger than a car.

Germanwings said the captain on board was experienced and had been with the airline and with Germanwings' parent company Lufthansa for more than 10 years and had clocked up 6,000 flying hours on this Airbus model.

Germanwings said the plane had a normal service at Dusseldorf yesterday and its last major check-up had been in summer 2013.