All 27,000 chickens at a farm in Suffolk will be culled after cases of bird flu were confirmed.
A number of the birds were found to have the H5 strain of avian flu, the Department for Environment, Food and Rural Affairs (Defra) said.
It has set up a 1km (0.6 mile) exclusion zone around the farm to limit the risk of the disease spreading.
Public Health England’s Dr Gavin Dabrera said the risk to public health was very low.
The Food Standards Agency said there was no food safety risk as long as poultry products, including eggs, are thoroughly cooked.
The strain at the commercial farm has been identified as “low pathogenic avian flu”.
Dr Dabrera, a public health consultant at Public Health England, said: “Avian flu (often called bird flu) is primarily a disease of birds and the risk to the general public’s health is very low.
“As a precaution, we are offering public health advice and anti-virals to those who had contact with the affected birds, as is standard practice.”
A detailed investigation is under way to determine the most likely source of the outbreak.
Chief veterinary officer Christine Middlemiss said: “Bird keepers should remain alert for any signs of disease, report suspected disease immediately and ensure they are maintaining good bio-security on their premises.
“We are urgently looking for any evidence of disease spread associated with this strain to control and eliminate it.”