Four snowboarders have died in an avalanche in the French Alps.
The victims, all reportedly French, were walking in an off-piste area of the resort of Tignes when they were hit by a massive wall of snow.
Images from the scene showed dozens of people with poles searching for survivors.
Tignes is popular with British skiers and this week is one of the busiest of the season as it coincides with school holidays in the UK and France.
The victims were a 49-year-old instructor, a 48-year-old father, his 15-year-old son and a 19-year-old half-brother, according to the Associated Press news agency.
Albertville deputy prefect Nicolas Martrenchard said: "We lament the four deceased victims and we think there will be only four. The search continues. It was an avalanche of a huge scale."
A rescue worker said the bodies of the victims were retrieved by early afternoon.
The avalanche, said to have been triggered by a group of skiers higher on the slope, is the worst on French slopes this season.
Fiona Best, PR manager at the Ski Club of Great Britain, described the area where the avalanche occurred, Lavachet Wall, as "notorious" and "quite a bit off piste".
She told the Press Association: "It's known to be a treacherous area to go to and with an avalanche warning of three out of five you would question whether or not you should really be heading over there."
Around 10cm (4in) of fresh snow fell on the slopes of the resort near the Italian border last week and more is forecast this week.
Experts said a strong wind and warmer temperatures had made an avalanche more likely.
Ms Best said nearly all UK tour operators offer trips to Tignes as there is a good range of skiing for beginners through to advanced and off-piste skiers.
"It's very popular with British tourists," she added. "I've been there for the last four years with my family."
The incident happened at around 2,100 metres (6,900ft) at 9.35am GMT on Monday.
Eight people had registered for the session with an instructor, according to reports.
Vicky Allen, a chalet rep, said: "There is a huge search effort still out. It's a very sad day for all of us working in the resort. It's devastating."
Richard Miller, an IT consultant from Cambridge, said: "I saw the piste patrol scrambling with dogs so suspected something was happening.
"Some of the lifts were closed this afternoon after staff were diverted to the search."
Three people had died in incidents in the French Alps and Pyrenees this year before Monday's avalanche.
An avalanche in the Apennines in central Italy last month left 29 dead after a hotel was crushed by tons of snow.