An avian quarantine unit was activated at the N S C Bose International Airport on Thursday to detect import of diseased chickens, particularly from Thailand.

As a preventive measure against the spread of bird flu, the Kolkata Municipal Corporation also decided to enforce a strict watch on the sale of chickens.

Also Read Bird flu claims eighth victim India bans poultry imports

Preventive steps had been taken against arrival of affected birds in accordance with the guidelines of the Union health ministry, airport sources said.

Member in the KMC's Mayor-in-Council (Health), Pradip Ghosh, visited some of the chicken stalls at the Hogg market in central Kolkata.

He directed KMC health officials to report any sale of diseased chickens.

The West Bengal government, alarmed by the spread of bird flu in South Asian countries, has stepped up vigil in all state-run and private poultry farms and formed a five-member committee for monitoring.