Specimens from dead chickens in Vietnam's southern Long An province have been tested positive to bird flu virus strain H5N1, Xinhua quoted local newspaper Youth as saying today. Tests by Vietnam's Regional Animal Health Center No. 6 have shown that some chickens of a 3,000-fowl flock raised by a household in Can Duoc district were infected with bird flu, the newspaper quoted Duong Minh Phi, deputy head of the province's Veterinary Bureau, as saying. Chickens in the flock started to die 10 days ago after developing bird flu symptoms, he said. The Department of Animal Health under the Vietnamese Ministry of Agriculture and Rural Development has yet to confirm the bird flu outbreak in Long An. Now, only southern Tra Vinh province is being hit by the disease, the department said. 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.