Authorities in Tripura on Sunday confirmed the presence of avian influenza virus in the Kamalpur area of Dhalai district.
"We received preliminary confirmation Sunday of bird flu in a bordering town Kamalpur, in remote Dhalai district," the state's top official Dr A Roy Barman who went to the spot for investigation told ANI over phone.
Over 3000 chickens, ducks, crows and other birds had first fallen sick and then died reportedly died during the past one week.
Barman said samples from dead birds were sent to the state-run High Security Research Laboratory in the central Indian city of Bhopal had tested positive for the deadly H5N1 strain of the virus.
Official said the culling would start on Tuesday.