Patna, Mar 14 (IANS): Nearly 6,000 chickens were culled and a large quantity of eggs destroyed in Bihar's Purnea district in the last five days following an outbreak of bird flu and officials asked to take all preventive measures to check the spread of the virus, an official said Thursday.

Rajesh Kumar, director of state animal husbandry department, said he has ordered the administration to keep a close watch on the situation for two months.

"Three blocks in the district have been declared high risk zones," he said, adding that the H5N1 virus was detected in chickens last week.

Kumar added that during a visit to Purnea Wednesday, he had directed officials to launch a continuous sanitation drive in the neighbouring districts too.

Purnea District Magistrate Manish Verma said culling operation had almost been completed for now.

"Now the situation is under control but more birds would be culled as a precautionary step. The administration had issued bird flu alert as a preventive measure. We are fully prepared to deal with an outbreak," he said.

Verma said 15 teams of officials have been formed to check the spread of bird flu and ensure that birds and eggs from the district were not sent outside Purnea, about 350 km from Patna.

An official of the animal husbandry department said the state government had also alerted neighbouring districts of Kishanganj, Katihar and Araria to take emergency measures.