An avalanche in the French Alps struck a high school ski group Wednesday afternoon, killing at least three people, according to French officials.

France's National Gendarmerie said a search-and-rescue operation was launched in the Deux Alpes ski resort using sniffer dogs and a helicopter.

French authorities in the Alps region confirmed that two high school students — a 14-year-old girl and a 16-year-old boy — and a Ukrainian skier died in the avalanche, which took place on a ski trail that had been closed amid avalanche warnings.

Officials said the avalanche hit 10 students and a teacher from the Saint Exupery school in Lyon. A telephone hotline has been opened in Lyon for relatives of those affected by the tragedy.

Local officials did not give any information on the number of missing but said 60 workers had been mobilized in the search-and-rescue operation.

Les Deux Alpes map

The avalanche, which occurred at the Deux Alpes ski resort about 50 kilometres from the Italian border, happened after a large sheet of snow broke off above a black-rated slope that had been closed following several days of heavy snowfall.

Cmdr. Bertrand Host said there had been warnings of a high risk of avalanches ahead of the slide. He spoke to BFM television from the avalanche site.

The regional Dauphine Libere newspaper reported that four of the students were found in cardiac arrest but their teacher was conscious.

French President François Hollande said in a statement Wednesday evening that the French education minister was on her way to Lyon. She was expected to arrive in the coming hours to "support the school community and the families."

Hollande said around 8 p.m. Paris time that mountain emergency services are still engaged in a rescue operation, and confirmed that three people have died so far and others are seriously injured.