Three new cases of bird flu have been reported at poultry farms in western and southern Poland.<br /><br /> The birds were immediately culled, and an area of 3 square kilometers was sealed off around each farm.<br /><br /> The H5N8 strain of avian flu is not considered harmful to humans but has been spreading across farms in Europe.<br /><br /> France, Germany, Bulgaria and Greece are among the countries to have reported outbreaks in recent weeks.<br />
