A worker wears a protective mask at Craigies poultry farm near Dunfermline as a cull of 40,000 chickens gets under way in Fife, Scotland, UK, January 13, 2016. [Photo/IC]

EDINBURGH - A bird flu case was formally confirmed at a poultry farm in eastern Scotland, the Scottish government said on Wednesday.

Laboratory tests identified a very mild strain of the H5N1 virus and a humane cull of almost 40,000 birds had begun, said the press release.

Restrictions on the movement of poultry and birds for one kilometer around the affected premises remain in place, it added.

Scottish Chief Veterinary Officer Sheila Voas said: "The lab has now formally confirmed the presence of a very mild form of H5N1 avian influenza on a poultry farm near Dunfermline. It is important to stress that this strain is quite distinct from the highly pathogenic form of H5N1 that has caused significant problems over the past decade or so around the world."

She stressed the precautionary measures in place since suspicion of disease was first reported, in line with well-rehearsed contingency plans for dealing with avian influenza, terming the formal confirmation as "something of a technicality."

Voas added that the restrictions around the premises would remain in force for 21 days after preliminary cleansing and disinfection, asking poultry keepers to remain vigilant for any signs of disease and to ensure they are maintaining good biosecurity on their premises.

The risk to human health in this case is considered very low and people were told that bird flu does not pose a food safety risk for consumers on the basis of current scientific evidence, said health protection experts.