Avian flu was reported from two more districts in eastern India where authorities said on Sunday that poultry farmers have fought a massive bird cull aimed at halting the spread of the virus.
A total of five districts in eastern West Bengal state have reported an outbreak of avian flu among poultry, the government said.
The outbreak is the third in India since 2006 and the worst so far, according to the World Health Organisation, partly because it is more widespread.
The state government aims to kill about 400,000 birds but poultry farmers have actively blocked access to many sites and attacked members of culling teams, a state minister said.
"The situation is grave. We are trying to control the situation," said West Bengal animal resources minister Anisur Rahman.
Residents oppose the culling because they want immediate compensation for dead birds, while the government says payments will take a few days. Around Dh770,000 (Dh2.8 billion) had been set aside for compensation.
Near Margram village – the epicentre of the outbreak – the biggest poultry farm with 30,000 birds remained untouched as the owner locked up the premises.
Many others fled their homes carrying chickens before the arrival of the culling teams, officials said.
West Bengal state borders Bangladesh, which is also fighting a bird flu outbreak.
Humans typically catch the disease by coming into direct contact with infected poultry, but experts fear the deadly H5N1 strain of the virus may mutate into a form easily transmissible between people.
Migratory birds have been blamed for the global spread of the disease, which has killed more than 200 people worldwide since 2003. (AFP)
India bird flu spreads as farmers resist cull