The Rescue 118 helicopter and Donegal Mountain Rescue have been called to help a person in difficulty on Errigal.
The call-out was reported shortly before 3pm this Sunday afternoon.
It is understood that a walker is in need of assistance on the mountain.
The Rescue 118 helicopter was involved in a separate mission on Saturday after two surfers got into difficulty in stormy seas off the coast of Sligo. The casualties were successfully recovered and handed over the National Ambulance Service.
