A total of 25 dead birds in Hungary have been found infected with the bird flu, with seven of them being confirmed to have been killed by the deadly H5N1 strain, a laboratory under the Animal Health Institute of Hungary said on Wednesday.

Most of the dead birds, including those infected by the H5N1 virus, were wild swans, and the rest included cormorants, sea crows, wild ducks and gulls. No domestic fowl have been hit by the disease so far.

Besides the seven confirmed H5N1 victims, the other dead birds have also been sent to Britain for further tests.

The authorities said they have taken certain measures against bird flu, including the designation of six protection zones and six observation areas where farmers have learned about the European Union's relevant rules and are obligated to observe them.

Hungary detected the first cases of H5N1 on three dead swans onFeb. 15.

Experts said more bird flu outbreaks are likely to occur in lakeside and riverside areas during springtime, but as bird migration ends in May, the chain of infection is expected to be cut off and the epidemic will thereby be curbed.