Sixteen German teenagers on a school trip to Spain were on board the aircraft that crashed in the French Alps on Tuesday killing all 150 passengers and crew, authorities said.
"This is certainly the darkest day in the history of our city," said Bodo Klimpel, the mayor of Haltern am See, the students' hometown in northwestern Germany.
"The city is deeply saddened ... Everyone is in a state of shock. It is the worst thing you can imagine."
The teenagers and their two teachers had been on a week-long exchange trip to Spain, and their names were on the passenger manifest of the doomed Germanwings flight, Klimpel told a news conference, fighting back tears.
Outside their school, fellow students lit candles and lay flowers for the victims, who were 10th graders studying Spanish.
Mayor of Haltern am See Bodo Klimpel speaks during a press conference. Source: AAP
French officials said there were no survivors among the 144 passengers and six crew aboard the Germanwings Airbus 320 jet when it crashed en route from Barcelona to Duesseldorf near the ski resort of Barcelonnette.
Klimpel said that, although rescue crews had not yet reached the crash site in a remote area of the French Alps, "we have to assume the worst".
Candles - some with names written on it - sit on a table tennis table in front of the Joseph-Koenig Gymnasium in Haltern, western Germany Tuesday, March 24, 2015. Source: AAP
"The relatives are being cared for by specialists, by counsellors and psychologists, and of course our thoughts are with the victims and their loved ones."
Klimpel said the high school, the Joseph Koenig Gymnasium, would Wednesday hold an event to honour the victims of the tragedy.
Two girls hug in front of the Joseph-Koenig-Gymnasium in Haltern, western Germany Tuesday, March 24, 2015. Source: AAP
"There will be an opportunity for the students to speak about the terrible thing that happened", said Klimpel.
Marti Pujol, mayor of Llinars de Valles, a village near Barcelona, said pupils at the Instituto Giola which the German visitors had attended during their exchange were being given counselling to help cope with the tragedy.
Condolences poured in on social media, including from a footballer who was born in Haltern, Germany, defender Benedikt Hoewedes.
"Everyone knows that I come from Haltern am See and I still have lots of friends and relatives there," the World Cup winner wrote on his Twitter account.
"I am unbelievably sad over this terrible accident and wish all the families and their loved ones the strength to get through this."