Two new bird flu cases confirmed in Norfolk and Suffolk during the weekend have deepened concerns for the region's threatened poultry farms.

Government vets found a highly-pathogenic strain of avian influenza in commercial poultry near Northwold, between King's Lynn and Thetford, on September 23.

The following day another case was confirmed at a commercial premises near Hadleigh in Suffolk.

A Defra statement says all birds at the infected premises will be humanely culled, while a 3km Protection Zone and a 10km Surveillance Zone has been declared around both sites.

The country is in the grip of its worst-ever bird flu outbreak, with more than 130 cases confirmed in England - including five in Norfolk and Suffolk in the last seven days.

On September 19, the disease was found in chickens at farms near Attleborough and the village of Honington, south of Thetford. A second premises at Honington was also confirmed on September 22.

The acceleration in East Anglian cases is becoming an increasing concern to the region's poultry industry, as the usual winter peak in infections looms.

John Newton, Norfolk county adviser for the National Farmers' Union (NFU), said: "These latest outbreaks highlight that avian influenza is still posing a risk in our region. It’s vital that all bird keepers practice good biosecurity, whether you are a commercial farmer or someone who keeps a small number of hens in the garden.

"Looking to the longer term, the government has provided funding for research into avian influenza which we hope will help us understand more about the disease and how we can prevent it, and ultimately put bird keepers in a better position to protect their flocks.

"We want to work with the government to minimise the impacts of any future outbreaks so we do not experience another year like this one."

In August, Defra lifted a national Avian Influenza Prevention Zone (AIPZ), which enforced stricter biosecurity rules for poultry and captive birds. While the risk to poultry was reduced to "low", it stressed that "scrupulous biosecurity" remains the best way for all bird-keepers to prevent outbreaks.

Although bird flu is potentially devastating to commercial poultry and wild bird flocks, Public Health England (PHE) advises that the risk to public health from the virus is very low and the Food Standards Agency advises that avian influenzas pose a very low food safety risk for UK consumers.