Experts fear that the H5N1 virus, which can be contacted by humans, could spark a pandemic if it mutates to the extent that it can be transmitted easily among people.

The ministry said the virus, of the H5N1 variety that can spread to humans, was found during routine checks. No birds were reported sick, it added.

Bird flu is most common during the cool, damp winter. The virus turned up last week in a farm in Hong Kong, leading to the culling of 80,000 birds.

So far this winter, bird flu has killed two people, in Indonesia and Egypt, and made two people ill in Indonesia and Cambodia.