The new outbreak of the avian influenza disease is in a mixed flock of 1,830 chickens, ducks and muscovy ducks of four small household farms at Lien Hoa in Quang Ninh province in the north of the country.
The outbreak began on 18 June, when 504 birds were found dead and 650 were affected. All birds have since been destroyed.
The presence of the H5N1 sub-type of the virus has been confirmed.
