Greece confirmed two more cases of H5N1 bird flu in wild swans on Wednesday following testing from a European Union laboratory in London, DPA reported. The lethal bird flu virus was found in two more wild swans, bringing the total number of wild birds infected with the disease to nine. The samples tested were collected from a group of wild swans in a lagoon in the northeastern prefecture of Rodopi, the Greek Agriculture Ministry said on Wednesday. So far, the bird flu cases in Greece have involved migratory birds and not poultry. Greek authorities have implemented a series of precautionary measures to stop the spread of the disease, including ordering all poultry farmers to keep their birds in coops, banning hunting and disinfecting within a radius of 10 kilometres of the sites where the dead swans were discovered near Thessaloniki. They said that all poultry would be banned from leaving farms in the zone except when taken to slaughter. Greek government officials banned the sale of live birds in street markets and have forbidden hunting in the area. The H5N1 strain of the virus, which has killed four people in neighbouring Turkey, has also forced other Balkan countries to cull thousands of poultry. Experts fear that H5N1 could evolve into a strain that could be passed from human to human, not just from birds to human as is currently the case, setting off a human flu pandemic.