China and Vietnam each confirmed new bird flu outbreaks which killed thousands of birds, despite increased efforts to fight the disease. The Asian Development Bank warned that a global flu pandemic could kill up to 3 million people in Asia and plunge the world into recession.

The latest Chinese outbreak, discovered on Oct. 26, killed 8,940 chickens and prompted officials to destroy 369,900 other birds in Badaohao, a village in Liaoning province, east of Beijing, the Agriculture Ministry said Thursday.

China has reported three other bird flu outbreaks since Oct. 14. No human cases have been reported, but authorities have warned that one is inevitable if the country fails to contain outbreaks in chickens and ducks.

In Vietnam, more than 3,000 poultry died or were culled this week in three villages in Bac Giang province, about 35 miles northeast of Hanoi, a local official said.

"We have taken all necessary measures to stamp out the outbreaks," said Nguyen Dang Khoa, the vice chairman of the People's Committee of Bac Giang province.

The deadly H5N1 strain of bird flu has killed at least 62 people — including 41 in Vietnam, according to World Health Organization figures — and resulted in the deaths of more than 100 million chickens in Asia since 2003.

Most human cases have been traced to direct contact with sick birds, but experts worry the virus could mutate and become easily transmissible between humans, possibly triggering a deadly flu pandemic.

In a report Thursday, the Asian Development Bank said that in a worst-case scenario in which the psychological impact of a pandemic lasts a year, Asia could lose almost $282.7 billion — or 6.5 percent of its gross domestic product — in consumption, trade and investment.

The report said "growth in Asia would virtually stop," and the economic impact would likely force the world into a recession. That scenario assumes about 20 percent of Asia's population would fall ill, and 0.5 percent would die.