Police said two hillwalkers in their 70s had died and a third who was also airlifted to hospital was still being treated.
A climber who was not named also died in an avalanche on a mountain south of Loch Ness in the Highlands.
Rescuers described struggling against "very challenging conditions," with winds blowing up to 140 kilometres (87 miles) an hour, in the search for a couple in their 20s who went missing at the weekend on Ben Nevis, Britain's highest mountain.
