A fifth case of bird flu has been confirmed near Attleborough - prompting another poultry cull in an area at the epicentre of a worsening virus outbreak.
Government vets have identified a highly pathogenic strain of avian influenza in a commercial flock of turkeys near East Harling.
Defra said all birds on the infected farm will be humanely culled, and a 3km Protection Zone and 10km Surveillance Zone were put in place around the premises.
It is one of more than 160 confirmed cases across the country in the UK's worst-ever bird flu outbreak, and the fourteenth in Norfolk and Suffolk since the start of September.
Another suspected case was also investigated at a poultry premises near Wymondham on October 4, but Defra has since revoked the temporary control zones there as the "disease has not been confirmed".
In recent weeks, tens of thousands of chickens, turkeys and geese have been culled - but government officials and farming leaders said this is still a small proportion of the nation's poultry production, and there is not currently expected to be a shortage of Christmas turkeys.
The disease is also rife in East Anglia's wild bird colonies, and the RSPB is reporting "distressing scenes" across the countryside, with dead swans and other birds being seen in numbers from the Broads to the beaches of north Norfolk.
Last week, the growing outbreak in the east of England sparked a raft of new restrictions in a bid to halt the spread of the disease.
The regional Avian Influenza Prevention Zone (AIPZ) makes it a legal requirement for all bird keepers across Norfolk, Suffolk and parts of Essex to follow strict biosecurity rules including disinfecting clothing, footwear, equipment and vehicles before and after contact with captive birds.
Although avian influenza can be devastating for wild birds and poultry flocks, the UK Health Security Agency advise that the risk to public health is very low and the Food Standards Agency says avian influenzas pose a very low food safety risk.
Poultry keepers and members of the public should report dead wild birds to the Defra helpline on 03459 33 55 77 and keepers should report suspicion of disease to APHA on 03000 200 301.
For full details on the requirements and boundaries of the AIPZ, see www.gov.uk/guidance/avian-influenza-bird-flu
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