Earlier, poultry died in mass with unknown cause in Phiêng Lương village, Đại Đồng Commune said head of the provincial animal health agency Nguyễn Nam Hưng.
After testing samples from the dead fowls, the agency found that they are positive to A/H5N6 virus. The local authorities later destroyed those suspected of virus infection.
The agency requested the public to stay away from sick and dead fowls and their droppings.
It also asked local authorities to spray chemicals to decontaminate farms while banning the sale, slaughter and transportation of poultry products in affected areas .