Special Report: Alps Plane Crash / France Plane Crash

A number of British nationals are thought to have been on board the crashed Germanwings aircraft, says Foreign Secretary Philip Hammond. All 150 people on the jet are thought to have been killed after the A320 plane plummeted into a remote mountain range in the French Alps and "disintegrated". The aircraft was en route from Barcelona in Spain, to Dusseldorf, Germany, when it came down on Tuesday morning less than an hour into its flight at Meolans-Revels, between Barcelonnette and Digne. A total of 144 passengers, including two babies, as well as two pilots and four cabin crew were on board the 24-year-old jet, operated by Lufthansa's budget airline. French aviation authorities said the plane did not issue a distress call and had lost radio contact with air traffic controllers at 10.53am. Meanwhile, some Lufthansa crews are refusing to fly "for personal reasons" which has led to some flights being cancelled, the airline admitted. Lufthansa said it was working on the assumption that the crash was an accident and any other theory was "speculation". Recovery teams have been flown in by helicopter to the remote region and one of the so-called "black box" flight recorders has been recovered. The debris appeared to have been spread over a wide area. Pictures showed many fragments as well as a wheel thought to be from the aircraft. German foreign minister Frank-Walter Steinmeier was flown over the the site and called it "a picture of horror". Gilbert Sauvan, from the local council, told Les Echos newspaper: "The plane is disintegrated. The largest debris is the size of a car." And Jean Louis Bietrix, a hiker who was accompanying a rescue team to the site, said: "There are no pieces anymore, there is nothing, there is nothing. The plane has totally disappeared." Mr Hammond said: "It is sadly likely that there were some British nationals on board the flight. We are providing consular assistance and will give further help as more information becomes available." There were believed to be 67 people from Germany on the aircraft, including 16 students and two teachers from the same school in the town of Haltern. The youngsters had been returning from a school exchange in Spain. German opera singers Oleg Bryjak and Maria Radner were also on board. Ms Radner had been flying with her husband and baby, said a Spanish opera house. Forty-five of the passengers are thought to be Spanish. No survivors have been found and the search for the wreckage was called off as night fell. It will resume in the morning. French interior ministry spokesman Pierre-Henry Brandet said he expected "an extremely long and extremely difficult" recovery operation because of the area's remoteness. Weather conditions were calm at the time the plane came down but they later deteriorated with rain falling. US officials said they did not believe terrorism was involved. France's President Francois Hollande said: "It's a tragedy on our soil" while German Chancellor Angela Merkel said her thoughts were "with those people who so suddenly lost their lives, among them many compatriots". She planned to visit the crash site on Wednesday. Germanwings chief executive Thomas Winkelmann told a news conference the pilot had more than 10 years' experience, including more than 6,000 flight hours on A320s. He said the firm would do everything possible to establish the cause of the crash.