Search and rescue volunteers and the police helicopter are currently looking for a missing 56-year-old from Amesbury.
Nigel Pinchbeck, from Gomeldon, was last seen in the Newton Tony area earlier today.
He is described as white, with short dark hair and glasses. It is not clear what he is wearing.
Police say concerns are growing for his welfare and are urging anyone who has information about his whereabouts to call 999 quoting log 48 of today.