The spokesman for the Croatian Agriculture Ministry, Mladen Pavic, told Hina on Tuesday morning that an analysis confirmed the presence of the lethal H5N1-strain in the dead swan.
Pavic added that competent authorities were taking necessary measures to prevent the spreading of avian influenza.
In Bosnia-Herzegovina the authorities have also taken the necessary steps, including the culling of local poultry, to contain the spreading of bird flu in the area around the Plivska Jezera lakes where two swans infected with the H5N1 virus were recently found.
According to the Associated Press news agency, seven EU nations - Austria, Germany, Greece, Hungary, Italy, France and Slovenia - have reported the disease's lethal H5N1 strain in wild birds.