Bird flu has killed poultry in southern Vinh Long province, raising the total number of localities in Vietnam stricken by the disease to five, according to a local veterinary agency on Friday.

Specimens from dead chickens in the province's Binh Minh district have been tested positive to bird flu virus strain H5N1, the Department of Animal Health under the Vietnamese Ministry of Agriculture and Rural Development said, noting that 20 chickens raised by a family died on Jan. 7.

Ten chickens in the affected flock were culled to prevent the spread of bird flu.

Bird flu has, since early December 2006, stricken 43 communes in 18 districts in the five southern provinces of Ca Mau, Bac Lieu, Hau Giang, Kien Giang and Vinh Long, either killing or leading to the forced culling of more than 42,000 poultry.

Specimens from many healthy unvaccinated ducks in the southern Mekong Delta have been tested positive to H5N1, the department said.

Recent local media reported a limited number of ducks and chickens have died in the last few days in several localities, including the two central provinces of Thua Thien Hue and Quang Nam, and southern Long An province. Specimens from the dead fowls are being tested for bird flu viruses.

Bird flu outbreaks in Vietnam, starting in December 2003, have killed and led to the forced culling of dozens of millions of fowls in the country.