Russia has confirmed a further outbreak of the bird flu virus.
The latest incident of bird flu in European Russia killed 12 hens at a private dacha. Authorities subsequently culled 53 ducks and hens at the locality and imposed a quarantine.
The outbreak was in Tambov, 400 kilometres southeast of Moscow last week, a senior regional animal health official said on Monday.
"Laboratory tests have confirmed the presence of the H5N1 strain (of bird flu) . . . in some dead fowl tissue samples," the official said.
Since emerging in 2003 in South Korea, the H5N1 avian flu strain has killed more than 60 people in four Asian countries and spread as far west as European Russia, Turkey and Romania.
Wild birds are carrying H5N1 as they migrate for winter, and countries in Europe, the Middle East and Africa are taking steps to try and stop the migrating birds from mixing with domestic fowl.
A spate of H5N1 cases or suspected cases in Europe in recent weeks has put authorities on alert at ports, airports and areas where migratory birds flock.