Tests have confirmed that a dead swan, found last week on the shores of the Sava River in southeast Zagreb, capital of Croatia, had been infected with the highly pathogenic H5N1 strain of bird flu virus, according to Croatia's state news agency Hina on Monday.

It was the third H5N1 case confirmed in wild swans in the country.

The Croatian Agriculture Ministry spokesman, Mladen Pavic, saidthat sufficient precautionary measures had been taken to curb the spread of the disease, and there was no need for additional ones.

But he stressed the importance of keeping domestic birds indoors, particularly when the migration of birds was at its most intensive stage.

Pavic added quarantine officers would continue to monitor the situation closely, though they had found no other evidence of possible infection after combing a three km area around the location where the swan was found.

Croatia, which lies under one of the main flight paths for migratory birds, reported its first H5N1 case last October in the eastern part of the country.

In late February this year, the disease hit the country's southern coastal region, where two dead swans were tested positive for H5N1.

Croatian authorities immediately adopted a series of measures, including ordering farmers to keep their poultry indoors so as to prevent them from contracting the virus from wild birds.

The authorities have also halted poultry imports from bird flu-hit nations, including Bulgaria, Greece, Italy and Slovenia.