India steps up vigil as bird flu spreads

Kolkata: Veterinary staff in east India are capturing chickens in night-time raids on the backyards of homes to surprise villagers unwilling to part with their poultry as the outbreak of bird flu spreads.

"It is very difficult to contain the virus among backyard poultry as villagers hide their chickens and even smuggle it to homes of distant relatives," said Anisur Rahaman, the state's animal resources minister.

Officials said they were worried about the disease spreading to the crowded state capital, Kolkata, after bird flu hit the South 24 Parganas district on Sunday, only 20 kilometres away from the city.

Surveillance was in place to stop infected poultry from being smuggled into one of India's biggest cities, they said.

The World Health Organization has said it is India's most serious outbreak of bird flu. Over 1.5 million birds have already been culled since the deadly H5N1 virus hit the state earlier this month.

Another half a million chickens and ducks will be slaughtered in the next few days, officials said.

Authorities said the virus could have come from neighbouring Bangladesh, also struggling to contain an outbreak of bird flu.