Swedish authorities said bird flu virus was found in two wild ducks in Sweden, but further tests are needed to confirm if it is the deadly H5N1 strain, Radio Sweden reported on Tuesday.
"Four tufted ducks were analyzed by the National Veterinary Institute (SVA) in Uppsala (north of Stockholm). Two of the birds were carrying bird flu virus," the Swedish Board of Agriculture said in a statement.
It said samples have been sent to the European Union laboratory in England for further analysis.
Swedish Agriculture Ministry said the situation is serious but not unexpected.