A poultry farm in Russian southern Rostov region has been quarantined following the avian flu deaths of about 35,000 birds in two weeks.

The farm had 500,000 chickens in total and lab tests have confirmed it was the bird flu.

Spokeswoman for the Emergencies Ministry in Rostov region, Marina Abrasion said the death of the birds was reported late November.

Preliminary analysis showed the birds died of the H5N1 virus, which has caused 207 human deaths worldwide since 2003.

The affected poultry farm has about a half-million birds.

The World Health Organization has warned that the virus could mutate into a form that is highly infectious among humans and easily transmissible from person to person.

Such a change could mark the start of a global outbreak.

MSM/BGH