Romania detected a new suspected case of bird flu close to the border with Moldova, in the eastern county of Vaslui some 100 km (60 miles) north of the Danube delta, the Agriculture Ministry said on Friday.

Earlier this month Romania became the first European mainland country to detect the deadly H5N1 strain of the disease which has killed more than 60 people and millions of birds in Asia.

The Danube delta on the Black Sea, Europe´s largest wetlands, is a major way station for migratory wild birds heading from Asia towards winter habitats in North Africa.

"A sample coming from a heron found on the shore of the river Prut, in Vaslui county, tested positive for bird flu anti-bodies," Agriculture Ministry spokesman Adrian Tibu said.

The presence of anti-bodies does not necessarily mean the birds have the deadly strain of the virus and further tests including at a centre in Britain must be carried to determine the type of the virus.

Farm Minister Gheorghe Flutur said the samples would be sent to a specialised laboratory in Britain as soon as possible to see whether the new case is the H5N1 strain of the disease.

Local officials said measures were being taken to help contain the virus.

"First of all we will tell people to keep chickens shut in their pens. We have closed the bird and animal markets," Ioan Zaharia, the government´s representative in the Vaslui county, told private TV station Realitatea.

The farm ministry said earlier in the day that hundreds of samples tested over the past few days across the country had proved negative, and that he hoped the measures taken would help contain the disease.

So far the deadly strain was found in samples taken from two villages in the Danube delta, 40 km (25 miles) away from each other. Authorities said 21,000 domestic birds in the two villages, which were quarantined, had been slaughtered.