Serbia confirmed on Thursday its first case of the deadly H5N1 strain of bird flu in a swan found last week in the northern Sombor region, close to the Croatian border.

The head of Serbia´s veterinary directorate, Dejan Krnjaic, said the result was confirmed by a reference laboratory in Weybridge, Britain. He said another swan found dead in western Serbia was also assumed to have had H5N1.

In both cases, areas within a 10 km (6 mile) radius of where the swans were found have been declared risk zones and veterinarians were monitoring all wild fowl within it. All domestic poultry in Serbia was being kept indoors.