Officials have said that hundreds of chicken were culled and large quantity of eggs destroyed in Bihar's Purnea district following an outbreak of avian flu.
Purnea district magistrate Manish Verma said the administration had issued bird flu alert as a preventive measure.
"We are fully prepared to deal with an outbreak," he said.
He said bird flu was detected after 300 birds of a government poultry farm died suddenly a few days ago.
"We sent blood samples for test. The results confirmed bird flu," Verma told IANS over telephone.
Verma said he had ordered culling of birds as a precautionary measure to check the spread of the virus.
An official of animal husbandry department said 15 teams of officials have been formed to check the spread of bird flu and ensure that birds and eggs were not send outside Purnea, about 350 km from here.
"All the entry of border along the district have been sealed and additional officials deployed to prevent traders from sending birds outside," an official said.
Purnea is a major supplier of chicken across Bihar and neighbouring West Bengal.