According to BBC news, the chickens at Norwich Road Farm and Mowles Manor Poultry Unit at North Tuddenham were slaughtered after tests showed they had the H7N3 strain.
Workers moved in on Sunday morning and began the cull of around 15,000 birds as the battle to stop the virus from spreading intensified.
David Collinson, Norfolk County Council's head of trading standards, said: "I want to reassure people who might see the signs that the restrictions only apply to the movement of poultry, captive birds and domestic mammals, but not pets.
"The orders advise all bird keepers within a declared zone to maintain high standards of biosecurity, and any movements of poultry and other captive birds within the zone must be licensed by a veterinary inspector."
Meanwhile, reports indicate that agriculture inspectors around the world are on alert for bird flu.
The World Health Organization warned on its Web site that the world "may be on the brink of another pandemic'' like the 1918 flu that killed as many as 50 million people.
While most attention has focused on the H5N1 strain, some officials say H7 viruses could mutate into a pandemic flu. It has so far spread from Asia to Europe, Africa and the Middle East, killing over 100 people since 2003. Unsuspecting victims contract the virus through close contact with sick poultry.
