Veterinary staff in West Bengal are capturing chickens in night-time raids to surprise villagers unwilling to part with their backyard poultry as an outbreak of bird flu spreads.
Bird flu has spread to 13 of West Bengal's 19 districts, with samples of dead chickens testing positive in two new districts, officials said on Monday. In neighbouring Bangladesh, the disease has spread to 29 of its 64 districts.
Experts fear the H5N1 strain found in both countries could mutate into a form easily transmitted from person to person, leading to a pandemic, but there have been no reported human infections in India yet.
"It is very difficult to contain the virus among backyard poultry as villagers hide their chickens and even smuggle them to homes of far-away relatives," said Anisur Rahaman, the state's animal resources minister.
Officials said they were worried about the disease spreading to Kolkata after bird flu hit the South 24 Parganas district on Sunday, only 20 kms from the city.
Surveillance was in place to stop infected poultry from being smuggled into one of India's biggest cities, they said.
Authorities also used loudspeakers and distributed leaflets in villages, urging people to hand over poultry to culling teams.
Villagers say government compensation of a dollar a bird is not enough.
"It's not just money, it is such a sentimental issue as villagers keep ducks and chickens as pets and also have different names to call them," Nazrul Islam of the West Bengal Poultry Association said.
West Bengal has promised to pay more money to villagers, admitting the virus could spread further if birds were not culled quickly. In Bangladesh, villagers have ignored or not heard advice on burying or burning dead birds, health officials say.
The World Health Organization has said it is India's most serious outbreak of bird flu.
More than 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.
The government says laboratory tests have confirmed the H5N1 strain in at least two of West Bengal's 19 districts, but said reports from 11 other districts were likely to be the same.
Authorities said the virus could have come from neighbouring Bangladesh, also struggling to contain an outbreak of bird flu.
Most countries and all Indian states have banned poultry products from West Bengal. But analysts said India's outbreak was too localised to have an obvious impact on the commodities markets.
"The domestic demand for corn might go down a little because of the bird flu, but it is still early to project what impact it may have," said Anmol Sheth, President of All India Starch Manufacturers Association.