Birds are set to be slaughtered at a large Norfolk poultry farm where an outbreak of avian flu has been confirmed.
A 3km-wide control zone has been declared around the unit at Pentney, near King's Lynn, by the Department for the Environment, Food and Rural Affairs (Defra).
It includes restrictions on the movement of poultry and other birds.
Defra said the highly pathogenic avian influenza H5N1 virus had also been confirmed at a farm at North Somercotes, near East Lindsey, Lincolnshire.
It added: "All birds on the infected premises will be humanely culled."
It is not clear how many birds are currently being housed at Abbey Field Farm, at Pentney, which stands at the grid reference issued by Defra as the centre of the control zone.
Satellite imaging shows 14 large sheds down a track off Abbey Road, which could contain thousands of birds.
People could be seen working on the site on Wednesday but a man who came to the gate declined to comment.
The outbreak is the second to happen in Norfolk this winter. A small number of birds were slaughtered last month after the virus was detected in a pet flock near Wells.
More than 70 outbreaks have been reported elsewhere since October, including 10 around Alford, in Lincolnshire and eight around Thirsk in North Yorkshire. The UK's chief vet has warned the disease is at "phenomenal" levels.
The National Farmers' Union said it did not comment on individual outbreaks.
Its regional director Gary Ford, formerly the union's chief poultry adviser, said outbreaks were "concerning news" for the poultry sector, which is worth more than £550m a year to the region's economy and supports 14,000 jobs.
He said all poultry keepers needed to follow biosecurity measures, be vigilant and report any signs of disease.
Official compensation ranging from £1 - £10.69 per bird is payable for table chickens and £1.13- £12 for egg layers, depending on their age.
But the money is only paid for flu-free birds, although farmers can buy insurance to cover the loss of their entire flocks and the cost of cleaning sheds after an outbreak.
UK food and health agencies say the risk to public health from the virus is very low and that avian influenzas pose a very low food safety risk for consumers.
Dead wild birds should be reported to Defra’s helpline on 03459 33 55 77 and poultry keepers should report signs of disease to APHA on 03000 200 301.
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