Buachaille Etive Mòr in more benign conditions. Stob Dearg is on the left, with Coire na Tulaich in the centre

Three mountain walkers were killed today and another was injured in an avalanche on Buachaille Etive Mòr.

Five others were caught in the avalanche and had to be rescued. The incident happened about 12.15 this afternoon, Saturday, and sparked a major rescue operation involving Glencoe Mountain Rescue Team, a helicopter from RAF Lossiemouth and a Royal Navy helicopter from HMS Gannet.

The mountaineers were caught in Coire na Tulaich, the major corrie under the western flank of the 1,022m (3,353ft) Stob Dearg, facing the main A82 road through Glencoe.

Four people were airlifted to Belford Hospital in Fort William. Police confirmed that one was pronounced dead at the hospital and a second person died later. The third fatality was that of a walker buried under avalanche debris on the mountainside.

The fourth mountaineer airlifted to hospital sustained a shoulder injury.

The five others rescued from Coire na Tulaich were uninjured. Search and rescue dogs were used to find casualties. It is believed the three who lost their lives were in a party of seven when the avalanche struck.

Writing on the Pistehors.com website, David Gunn, a paramedic with the Glencoe rescue team, said the three were swept 150m (500ft) from a scarp slope – that is, below a cornice – and were suffering cardiac arrest. They were on the normal ascent route up Buachaille Etive Mòr.

Two of the walkers were dug out of the avalanche by their companions, and the other located by a spot probe.

Resuscitation attempts at Belford Hospital were unsuccessful.

According to Mr Gunn, the route has seen many fatal avalanches over the years.

The avalanche forecast for the day, available from the sportscotland Avalanche Information Service, put the risk at category three – classed as ‘considerable’. Risk is rated on a scale of one to five, with five being the most severe. Highest chance of snow breaking away was said to be on north-west and northern aspects.

Coire na Tulaich’s slopes are on the north-western side of Stob Dearg. Snow showers and south-westerly winds had caused a build up of soft slab, only loosely bound to the existing snowpack.

The avalanche risk for tomorrow in Glencoe is set to rise to level four – ‘high’.

Police have not yet released the identity of the dead mountaineers. They are still trying to contact next-of-kin. They said two of the dead men were from Northern Ireland and the other from Scotland.

Staff from the nearby Glencoe Mountain ski centre also went to the walkers’ aid when the incident happened.