Two villages in an eastern Indian state that appeared to have brought a widespread outbreak of bird flu under control last month have reported fresh cases of the disease, officials said on Sunday.
The new cases were confirmed a month after a massive cull that slaughtered almost 3.8 million chickens and led West Bengal to lift a ban on the sale and transport of poultry across the state.
"Laboratory tests confirmed bird flu on Friday night in two villages of Murshidabad district," Subir Bhadra, a senior official in the district bordering Bangladesh, which is also battling avian flu, told AFP.
Samples were sent for testing after almost 1,000 chickens died there in the past week, the official said.
The district was one of 13 battling the deadly H5N1 strain of bird flu at the peak of the outbreak early last month, when more than half the state was reporting bird flu cases.
"We are very concerned over the fresh outbreak," said state animal resources minister Anisur Rahaman.
"Health workers have been asked to cull all poultry in the district in a day or two."
The West Bengal outbreak, which began in January, is India's third and worst bout of bird flu.
No cases of human infection have been reported so far in India.