Four new cases of bird flu have been confirmed in Norfolk - heightening the pace of an epidemic which is devastating the county's poultry industry.

Vets have identified a highly-pathogenic strain of avian influenza in commercial housed poultry near Holt, Mundford and Attleborough - the latter becoming the eighth case near the Breckland market town. Defra says all poultry on these farms will be humanely culled.

The disease was also confirmed in a mixed flock of captive birds at Oxborough, near Swaffham, where all affected birds will also be culled.

It adds to the mounting toll of tens of thousands of chickens, turkeys, geese and ducks which have been slaughtered in recent weeks.

There have now been 10 confirmed bird flu cases in Norfolk since the start of October, with more across the border in Suffolk, making East Anglia the epicentre of the UK's worst-ever bird flu outbreak.

It has become a major concern for both the region's nationally-important poultry industry, and its treasured wild colonies of coastal and wetland birds.

At the weekend, the UK's chief vet announced a regional lockdown will be enforced for all poultry and captive birds in Norfolk, Suffolk and parts of Essex from October 12 in a bid to stop the spread of the virus.

The mandatory housing order makes it a legal requirement for all bird keepers in these hotspots to "keep their birds indoors and to follow stringent biosecurity measures to help protect their flocks from the disease, regardless of type or size".

Although avian influenza can be devastating for wild birds and poultry flocks, the UK Health Security Agency advise that the risk to public health is very low and the Food Standards Agency says avian influenzas pose a very low food safety risk.

Poultry keepers and members of the public should report dead wild birds to the Defra helpline on 03459 33 55 77 and keepers should report suspicion of disease to APHA on 03000 200 301.