At least four people have died in an avalanche at the ski resort of Tignes in south-eastern France, rescuers say.

The group was buried after the wall of snow swept through an off-piste area, police say.

Some reports say there were nine in the group, including a guide, and that the other five remain missing, trapped in the snow.

However, local police have told the BBC that the other five may have failed to show up for the session.

The 400-metre (1,300ft) wide avalanche occurred at an altitude of 2,100 metres, and struck at a particularly busy time during half-term holidays.

The resort is popular with British holidaymakers, but local police said the four dead skiers were all French nationals.

The avalanche appeared to have been set off by a group of skiers higher up, the ski station said in a statement.

Rescue services deployed two helicopters as well as sniffer dogs to help search for the missing skiers. There are about 40 people involved in the rescue operation.

The incident is the worst in France since the beginning of this year’s ski season.

The avalanche warning level at Tignes on Monday was three out of five, France’s Dauphine Libere reported.

There were 13 previous skiing accidents in the Alps and Pyrenees this winter, killing three people.

Last winter, there were 45 accidents, causing 21 deaths.