Bird flu has been found in chickens near Haltwhistle.
The UK’s Chief Veterinary Officer confirmed the disease in a small flock close to the town, east of Cumbria.
A 3km protection zone and a 10km surveillance zone have been put in place around the infected site.
The Department for Environment, Food and Rural Affairs said this was to limit the risk of the disease spreading.
A spokesman said: "The flock contains about 35 birds.
"A number have died and the remaining live birds at the premises are being humanely culled.
"A full investigation is under way to determine the source of the infection."
Officials say the risk to public health from the virus is very low.
The Food Standards Agency says bird flu does not pose a food safety risk for UK consumers.
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