A protection zone was set up following a case of avian flu on a commercial poultry farm.
The Department for Environment, Food and Rural Affairs (Defra) said the H5N1 virus was confirmed on Sunday at a property near Lakenheath, Suffolk, and all birds would be culled.
A 3 km (1.9 mile) protection zone and a 10 km (6.2 mile) surveillance zone have been put in place around the premises and will remain in place until the declaration is withdrawn.
It is the first confirmed case in the east of England since an outbreak near Attleborough in Norfolk in August.
The disease is caused by a virus that infects birds and sometimes other animals, including foxes, seals and otters.
Defra said the risk to the public was very low, but people should not touch or move dead or sick wild birds.
