THE deadly H5N1 virus has killed 400 chickens in central Thailand, in the first outbreak of bird flu in 10 months, livestock officials said Thursday.

The outbreak was confirmed by laboratory tests after the poultry deaths were reported Monday by a farm in the Chumsaeng district of Nakhon Sawan province, about 210 kilometers (130 miles) north of the capital, Bangkok, said Somboon Srisupthep, head of the province's livestock department.

About 50,000 chickens being raised at the farm were expected to be slaughtered later in the day to contain the virus, Somboon said.

The outbreak is the first in Thailand since March 18, 2007, when about 50 ducks and chickens were found dead in northeastern Thailand.

Bird flu remains hard for people to catch, but health experts worry the virus could mutate into a form that passes easily among humans, sparking a pandemic. So far, most human cases have been linked to contact with infected birds.

At least 219 people have died worldwide from the virus, according to the World Health Organization.

AP