Greece and Bulgaria have stepped up efforts to control the spread of bird flu after the disease was found in wild swans.
The H5N1 virus has been found in wilds swans in the Bulgarian wetland region of Vidin, close to the Romanian border.
Authorities in Bulgaria have banned people from entering frozen wetlands near the Black Sea and advised farmers to keep their poultry indoors.
Similar warnings are being given in northern Greece.
It was announced yesterday that three swans had tested positive for bird flu in Greece, reporting along with Italy the first cases of the deadly strain of the disease brought by migratory birds into the European Union.
The deadly H5N1 strain of the virus has killed at least 88 people in Asia and the Middle East since early 2003 and forced affected nations to cull millions of domestic fowl.
Health experts fear it could mutate into a form that passes easily between humans, possibly triggering a pandemic that could kill millions.
