All 150 passengers and crew on board an Airbus plane operated by Germanwings are presumed dead after the aircraft crashed in the French Alps region.

There is no hope of finding any survivors on board, French police said on Tuesday.

"There is no need for any rescue operations, everyone is dead," said a police officer in the town of Le Vernet, near the crash site, according to the AFP news agency.

French Interior Minister Bernard Cazeneuve said later on Tuesday that one of the black boxes from the plane was found.

Germanwings said the Flight 4U9525 plane, which was travelling from Barcelona in Spain to Dusseldorf in Germany, started descending one minute after reaching its cruising height and continued losing altitude for eight minutes.

"The aircraft's contact with French radar, French air traffic controllers ended at 10:53am (9:57GMT) at an altitude of about 6,000 feet (approximately 1,825 metres). The plane then crashed," Lufthansa unit Germanwings' Managing Director Thomas Winkelmann told reporters.

He said that routine maintenance of the aircraft had been performed by Lufthansa Technik and there were no abnormalities with it.

'Germans, Turks and Spaniards were on board'

In a live briefing earlier, French President Francois Hollande said: "There were German and Turkish victims. There should be no French victims but I am not completely certain ... We are in mourning," he said. "It's a tragedy on our soil."

A spokesman for Spanish Deputy Prime Minister Soraya Saenz de Santamaria said that some 45 people travelling on the plane had Spanish surnames.

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 German spokeswoman said.

In a brief press conference, German Chancellor Angela Merkel said she would travel on Tuesday to the French Alpine region where the plane crashed.

She said her foreign and transport ministers, Frank-Walter Steinmeier and Alexander Dobrindt, were to head to the area, in a mountain range known as "Les Trois Eveches".

"There is a strong suspicion" that the students and teachers were on the doomed airplane, said the spokeswoman from the town in North Rhine-Westphalia state. "We don't have any official confirmation yet."

'A loud noise, then nothing'

The owner of a camping site in Alpes-de-Hautes-Provence said he heard the plane come down.

"There was a loud noise and then suddenly nothing. At first I thought it came from fighter jets that often hold drills in the area," Pierre Polizzi told Al Jazeera.

Eric Ciotti, the head of the regional council, said French search-and-rescue teams were headed to the crash site at Meolans-Revels.

"The plane crashed just 2km from here, high on a mountain," Polizzi, owner of Camping Rioclar, said.

French TV reported that 240 local firefighters and three police squadrons were mobilised for the rescue effort.

The single-aisle A320 typically seats 150 to 180 people.

"Germanwings has outstanding safety records. This is the first fatal incident involving the the airline," Al Jaeeera’s Dominique Kane, reporting from Berlin, said. "Airbus, the manufacturer of the plane, has serious concerns about the incident and wants to find out what actually has happened."

Germanwings is the low-cost subsidiary of Germany's Lufthansa airline.

Airbus delivered the plane to Lufthansa in 1991, after which it flew exclusively for the German flagship carrier until it was transferred to Germanwings' fleet last year.

Al Jazeera