Three new cases of the deadly H5N1 virus were confirmed yesterday from swans found at the Evros River on the Greek-Turkish border while the number of dead migratory birds found in Greece is showing signs of slowing down, authorities said. State veterinary services said that fewer birds have been reported dead in northern Greece in the last few days as the weather improves. A total of 120 migratory birds were tested in January for the disease while the figure fell to 98 in February. Meanwhile, four more samples were also sent off to the EU lab in Weybridge, England, yesterday after initial tests found that they had been infected with bird flu, bringing the total number of birds found with the virus to 22. Officials added that they will increase tests conducted on dead birds found in cities, such as pigeons, to determine whether they are being infected by the H5N1 strain. Experts say that the virus is mutating steadily and may eventually acquire the changes it needs to be easily transmitted from human to human.