The deadly bird flu virus spread to a new district in West Bengal as authorities said on Monday villagers' resistance to culling operations and poor health awareness was slowing efforts to stamp out the disease.
The H5N1 virus was found among dead birds in Bankura district of West Bengal. Now six of the 19 districts in the communist-ruled state have been infected with the disease.
Around 20 million people live in these infected areas.
The virus was also spreading to new areas within already infected districts and the state was finding it difficult to contain the disease.
"There are difficulties and the virus is moving from one place to the other," Sanchita Bakshi, the state's health services director told Reuters.
"We have to take emergency measures now to tackle the situation," she added.
Culling of poultry came to a halt on Sunday in many places as Muslims, observing the first Muslim month of Muharram, refused to hand over birds for culling.
Only 125,000 birds were culled since last week and officials said they would need more time to slaughter over 500,000 birds.
Many farmers were still dumping dead birds in lakes and ponds, ignoring repeated warnings by health workers.
"The villagers are unaware of the dangers and were using bare hands to hold sick birds, which is dangerous and can potentially spread the disease further," health minister Surjya Kanta Mishra said.
India is yet to report a human infection, but health workers were watching for people with flu symptoms in the affected areas, officials said.
Experts say the virus might mutate into a form easily transmitted from person to person, leading to a pandemic affecting a fifth of humanity.
Television pictures showed children playing with dead and sick chickens in Birbhum district, the epicentre of the fourth bird flu outbreak among poultry in India since 2006.
In some places, veterinarians were beaten up by villagers and thrown out of poultry farms.
"How can we let them kill our healthy birds, besides we have spent all our savings to build the farm," Rahamat Ali, a poultry farm owner said by telephone from Tehatto in Nadia district.
Clearly worried at the development, the rapid response team was increased to 400, with health workers from neighbouring Assam state joining the culling operation.
Holidays of health workers were cancelled as bird deaths were reported from many areas of the state.