This is the terrifying moment a huge avalanche cascaded down a mountainside, engulfing dozens of skiers who desperately tried to escape. 

Dramatic footage captured the mass of snow and ice tumbling down a steep slope near the Italian resort of Courmayeur on Tuesday. 

In the clip which has been shared on social media, a large group of skiers were seen waiting by a chairlift on the other side of the mountain, looking up in horror and excitement as the barrage of snow ploughed towards them. 

The thick, roiling mass of snow quickly gathered speed and ploughs over a row of tall pine trees. 

Onlookers appeared fascinated by the snowslide as it came down the mountain. 

But upon seeing it tower over them, their captivation turned to terror at the last second. 

Dozens of skiers, many of whom appeared to have young children with them, tried to flee the area at the last second but were engulfed in a cloud of snow. 

It is unknown if anyone was injured. 

The avalanche, which unfolded near the Zerotta chairlift in Val Veny, comes just days after two skiers were killed in a similar incident in the same resort. 

The tragedy occurred on Sunday on the Couloir Vesses, a well-known freeride route, Italy's Alpine Rescue said.

One of the victims was taken to a hospital in serious condition but later died.

Fifteen rescuers, three canine units and two helicopters took part in the search and rescue efforts.

Courmayeur, a town with about 2,900 inhabitants, is 124 miles north-west of Milan, one of the venues hosting the Milan-Cortina.

Resorts in Italy have been placed under high avalanche alerts after fresh snowfall on weak internal layers have led to risky conditions for skiers. 

Meanwhile, a number of Brits have also been killed skiing in the French Alps this winter. 

On Tuesday, a British national who lived in Switzerland had been killed in an avalanche.  

The slide struck the Côte Fine couloir in La Grave on Tuesday morning.

Two skiers were found in cardiorespiratory arrest and later pronounced dead, according to Marion Lozac'Hmeur, Public Prosecutor of Gap.

One man, born in 1987, was Polish. The other, born in 1989, was a British national originally from Poland who lived in Switzerland.

The French guide was injured and taken to Grenoble University Hospital. Two skiers, from Germany and Australia, escaped unhurt.

Just days before an avalanche in Val-d'Isère swept away six skiers in an off-piste area of the slopes, killing one French national and two Britons. 

The Brits were named as Stuart Leslie, 46, and 51-year-old Shaun Overy on Monday night.

Swept hundreds of metres down the mountainside, they were carried into a stream at the bottom of the slope, where rescuers later recovered their bodies. 

A French national skiing alone higher up the mountain was also killed. A third Briton survived with minor injuries after reportedly digging himself out of the snow. 

Emergency services responded quickly but could not prevent the deaths, a resort official said, noting that all of the victims had avalanche transceivers.

The deaths occurred less than 24 hours after the Savoie region was placed on a rare red avalanche alert - a warning level issued only twice before in the 25 years since its introduction.

Although the alert had been lifted by Friday morning, the risk remained at four out of five – officially 'high' – with avalanches 'easily triggered by skiers or hikers' and capable of mobilising 'very large volumes of snow'.

Skiers are warned against going off-piste when the avalanche danger level is above tier three.

Storm Nils had blanketed the area with up to a metre of fresh snowfall on Thursday, leaving what Météo-France described as a 'very unstable snow cover'.

Several resorts, including La Plagne, Les Arcs, Peisey-Vallandry and La Grave, were forced to close.

The group had been skiing under the supervision of an instructor, who was unhurt. Alcohol and drug tests were negative.

The instructor is alleged to have ignored safety warnings before the avalanche which killed the men.

The area had been issued a tier four warning when they took to the slopes. A day earlier the avalanche risk level was at five out of five - the first time in 17 years. 

Cédric Bonnevie, Val d'Isère's piste director, said: 'We can’t prevent people from going off-piste. We can’t hold everyone’s hand and there isn’t much we can do unless we close the slopes, which we don’t normally want to do.'

A manslaughter investigation has been launched by the CRS Alpes mountain rescue police, as is routine in fatal mountain accidents, under the direction of Albertville prosecutor Benoît Bachelet.

Mr Bonnevie said the avalanche tore down the slope for 400 metres before ending in a stream.

He said the cause remains unknown, though French media suggested it may have been triggered by the solo skier above the group.

Rescuers located two of the victims within 15 minutes, as they were equipped with avalanche transceivers.

But finding the third body proved more challenging when it emerged that the device was submerged underwater and no longer functioning.

Dogs and probes were deployed before the body was recovered hours later.

Mr Bonnevie told The Telegraph: 'This is always a sad situation. Three people in the same avalanche is so tragic.'

The majority of fatal winter sports accidents in France, Switzerland, Austria and Italy occur off-piste rather than on secured runs.

Avalanches account for around half of those deaths, with France averaging about 25 fatalities each winter.

This season alone, there have been at least 25 avalanche deaths across the country.