A spokesman for Northern Constabulary has said that the three people airlifted to hospital are "believed to be in a serious condition".
He added that two groups of six people had been in the area at the time of the avalanche, and have now been "walked off" the hill.
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Sunny and dry for most on Monday although rain affects much of Ireland.
The band returned to the festival - a decade after a disastrous set - as the iconic festival drew to a close on Sunday.
The band dedicated their song Everlast to fan Laura Plane, who died from breast cancer last month.