While describing the bird flu as very serious, Chief Minister Buddhadeb Bhattacharjee added that the death of crows, hawks, owls and vultures was normal and that there was no cause for panic.

“We will have to kill four lakh birds in the affected districts. For this, we have decided to increase the strength of the culling teams,” Bhattacharjee told newsmen here after a high level meeting with Central Livestock Commissioner S K Banerjee, State Animal Husbandry Development Minister Anisur Rehman and Health Minister Dr S K Mishra.

Poultries within a radius of 5-10 kms of the affected areas would have to be culled and the process will be completed in seven days, he said even as fresh areas in Burdwan, Nadia and South 24 Parganas besides Murshidadbad districts have been afflicted with the disease.

Some birds were found dead in southern and eastern parts of the city on Friday, triggering panic among residents. A civic team moved round the metropolis to collect bird carcasses while culling operations in Birbhum and South Dinajpur districts continued at a very slow pace.

“We are informing the state Health Department to ascertain whether the deaths were usual or unusual,” a civic department official said.

“There is no report of any outbreak of the disease in poultries in Kolkata; neither is there any report of any person affected by the disease so far from anywhere. However, an alert has been sounded in the city," Bhattacharjee added.

‘Don’t dump fowl’
Meanwhile, health workers urged villagers at Margram in Birbhum district, the epicentre of the outbreak, to stop dumping dead fowl in ponds, as ignorance about the virus has been hampering efforts to contain its spread.

In many of the quarantined villages, bare-chested villagers picked up dead birds with their hands and dumped them in ponds, increasing the risk of the virus spreading. “There is always a risk of contamination of water and the virus affecting other animal species,” a state health official said.

The World Health Organisation had already cautioned that the outbreak of avian influenza in Bengal is far more serious than the pandemic in Manipur and Maharashtra. Culling operations continued for the third day at worst hit Rampurhat I, II and Murarai and other blocks of Birbhum district and in South Dinajpur district.