One man has been airlifted to Aberdeen Royal Infirmary and mountain rescue teams are continuing their search for two other people, police said.
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The Grammy-winning singer posted a picture of the two on his Instagram saying the two got engaged right before the new year.
British Airways said it was taking the matter "extremely seriously" and is assisting police with their enquiries.
The rest of this weekend will see further spells of rain or snow across the UK. Icy roads expected