"Regarding the samples in Caraorman, the laboratory in London confirmed it was the highly pathogenic H5N1 virus," the ministry said on its website.

Romania said on Nov. 14 that four new cases of avian flu in domestic birds had been discovered in Caraorman. The village, which has no road access, was quarantined and around 2,000 domestic birds were slaughtered last week.

The ministry said the bird flu virus had also been isolated in five swans found in the gulf of Muzura, near the border with Ukraine, and in three other wild birds found near the village of Obretinul Mic, about 10 kilometres (6 miles) north of Caraorman.

Samples will be sent to the laboratory in Weybridge, near London, to determine whether it is the H5N1 strain, the ministry said, but did not say when the results would be known. Spokesman Adrian Tibu said the Agriculture Ministry was conducting random tests to track the spread of bird flu.

"We monitor wild birds, shooting some of them to see how far the virus is spreading. We keep testing domestic fowl," he said.

Tests on poultry sent to check whether the disease was still present in the village of Maliuc -- where the H5N1 strain was detected in October -- were negative, the ministry said, and all restrictions imposed on villagers had been lifted.

The H5N1 strain has killed more than 60 people in Asia since 2003 and led to the slaughter of millions of domestic birds. Scientists fear the virus might mutate into a form that could be easily transmitted between humans.