A Northern Constabulary spokesman said: "Emergency services are currently responding to an avalanche in the Cairngorm mountains today.
"The avalanche was reported to have happened shortly after 12.30pm this afternoon in the Chalamain Gap area of the Cairngorms.
"Officers from Northern Constabulary are being assisted by members of Cairngorm Mountain Rescue Team, SARDA (Search and Rescue Dog Association) Scotland dogs, RAF Lossiemouth MRT and RAF helicopter 137 also from Lossiemouth."
Earlier this week, a hillwalker died during an expedition with a mountaineering club in the Cairngorms.
Graham Connell, 31, from Castleford, West Yorkshire, was found dead in the Jacob's Ladder area on Monday, following a large-scale search for him and five other people who were reported overdue on Sunday afternoon.
The other members in the party, who were unhurt, were picked up by an RAF rescue helicopter after being located by Braemar Mountain Rescue Team on a hill near Carn Tarsuinn.
The search, co-ordinated by Northern Constabulary and Cairngorm Mountain Rescue Team, involved more than 100 people.
The walkers were part of a larger group of 35 people visiting the Highlands.
In a separate incident earlier this month, three men survived falling 150 metres in an avalanche in the Coire an t-Sneachda area of the Cairngorms.
The men, who were wearing helmets, were airlifted to hospital with leg injuries.
The avalanche, on Saturday February 2, was the second in the region that day.
In January, four people were killed in an avalanche in Glencoe.
Hospital doctor Rachel Majumdar, 29; PhD student Tom Chesters, 28; Christopher Bell, 24, also a PhD student; and 25-year-old junior doctor Una Finnegan died after they were caught up in an avalanche on Saturday January 19.