A stone marten in Germany is thought to have been infected with the H5N1 bird flu virus in what is believed to be the first case of a member of the weasel family catching the disease in the wild.

The stone marten was found on the Baltic Sea island of Ruegen near where three dead cats were discovered which all tested positive for the most dangerous form of the virus.

In Nigeria, 60 people who had been under observation due to bird flu-like symptoms were all cleared of the virus after medical tests proved negative.

Earlier, Serbia confirmed its first case of H5N1, in a dead swan found last week in the north of the country close to the Croatian border.

The result was confirmed by the European Union laboratory at Weybridge in Surrey.

Another swan found dead in western Serbia was also assumed to have had H5N1.

In both cases, areas within a 10km 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.