According to tests by Vietnam's Central Veterinary Diagnosis Center, the four civets were infected with H5N1. Specimens from a civet in the national park in northern Ninh Binh province, which died on March 2, has been tested negative to the virus.

The park's staff named Tran Quang Phuong said that after the deaths of five Owston's palm civets in late February and early March, there are now eight civets in the park.

In June 2005 when bird flu was hard hitting Vietnam, three Owston's palm civets in the national park died. According to tests by a laboratory in China's Hong Kong, they were infected with H5N1.

It has remained unknown why the civets have been infected with the disease, the newspaper said.

Vietnam's Department of Animal Health on March 10 said the country currently has nine localities having poultry being hit by bird flu: Quang Ninh, Hai Duong, Nam Dinh, Tuyen Quang, Ninh Binh,Phu Tho, Ha Nam and Hanoi in the northern region, and southern Vinh Long province.

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.