UK deputy chief veterinary officer Graeme Cook has today (February 13) announced an initial 10km Temporary Control Zone around a poultry premises near Redgrave, mid-Suffolk.
Laboratory investigations confirmed the presence of the H5N8 strain of Avian flu in an affected 23,000 birds.
A number have died and the rest are due to be culled.
Further investigations are said to be continuing into the nature of the virus detected and to establish the possible source of the infection.
The controls, an inner 3km Zone A and an outer 10 km Zone B, are equivalent to those which would apply around a confirmed case of bird flu.
The zone covers areas of both Suffolk and Norfolk.
The cause of the infection is not yet known.