An outbreak of bird flu has been confirmed in Norfolk, the government said.
The H5N1 virus, which is highly contagious and can kill poultry flocks, was found at the Holkham Estate near Wells-next-the-Sea.
Temporary control zones of 3km (1.8 miles) and 10km (6.2 miles) have been put in place around the affected site.
It is the third confirmed outbreak recently in the east of England, following two in Essex this month.
Holkham Hall confirmed the Norfolk outbreak was in a small domesticated flock of chickens and turkeys kept at a residential property on the estate.
The Department for Environment, Food and Rural Affairs (Defra) said a number had died and the others would be "humanely culled to limit the risk of onward transmission".
A spokesman said further tests were being carried out to determine the pathogenicity of the Norfolk case.
Avian flu is spread by close contact with an infected bird, whether it is dead or alive.
The Defra website says the virus is "primarily a disease of birds and the risk to the general public's health is very low".
An Avian Influenza Prevention Zone (AIPZ) has been in place across Great Britain since 3 November, and outbreaks have been recorded in Cumbria, Warwickshire, Cheshire and North Yorkshire.
The order means bird keepers need to follow strict biosecurity measures to help protect their flocks.