CALCUTTA - THE deadly H5N1 strain of bird flu has been found in samples taken from dead chickens in eastern India, authorities said on Monday.

It was the second outbreak of bird flu in India's West Bengal state and came as several thousand birds have been slaughtered in the neighboring state of Assam, where authorities have been battling an outbreak for several weeks.

Tests from samples taken from the village of Lorhata, some 354 km north-east of Calcutta, the capital of West Bengal, showed the presence of the H5N1 strain of bird flu, said Sirthar Kumar Ghosh, a local official.

Mr Ghosh said authorities would begin slaughtering birds on Tuesday.

Some 3,500 birds have died in Lorhata in recent days.

India has contained several previous outbreaks of the disease, including in West Bengal in January, when they slaughtered some 4 million birds.

No humans in India are known to have caught the disease, which has killed at least 246 people worldwide according to the World Health Organisation.

Bird flu remains difficult for humans to catch, but experts fear the virus might mutate into a new form that spreads easily among people, potentially sparking a pandemic. -- AP