Bird flu [Images] continued to spread in West Bengal on Thursday as three more districts of the state reported poultry deaths. The World Health Organisation warned that the outbreak in the state was far more serious than the previous pandemics in Manipur and Maharashtra.

The Centre also admitted that the outbreak of the deadly disease was on a wider scale than the two earlier outbreaks in Maharashtra and Manipur.

Culling operations, to target nearly four lakh poultry, continued at a slow pace for the second day amid confusion about the figures of the birds killed.

West Bengal Animal Resources Development minister Anisur Rahaman told reporters in Kolkata that Bird Flu had spread to Kirnahar in Birbhum district and Barwan in Murshidabad district since Wednesday.

He said there were also reports of poultry deaths in neighbouring Burdwan, South 24 Parganas and Nadia districts, but there were no bird flu symptoms.

"There are reports of unusual mortality in Terhatta block of Nadia district, Kalna block of Bardhaman district and Baruipur village of South 24 Pargana district," Union Animal Husbandry Secretary Pradeep Kumar said.

Samples are being collected from the new areas and they will be sent to the High Security Animal Disease Laboratory, Bhopal.

"Fresh cases of mortality have been reported from Khargram and Burwan blocks of Murshidabad district, which are adjoining to the affected area of Birbhum," Kumar said.

He added that fresh mortality of 247 poultry birds have also been reported from Gangarampur block in South Dinajpur district, where the deaths were restricted to the state farm till Wednesday.

As per latest information, at least 61,075 poultry deaths have been reported from Birbhum, South Dinajpur and Murshidabad.

Commenting on the WHO warning, Kumar said it was true that the outbreak was much wider than in the earlier cases. He said, "The scale is wider but the government is alive to the problem".

He said there was no cause for panic as reports of deaths from other areas was not large scale. "We cannot overreact to a situation," he said.

"The situation is under control and no reports of unusual mortality in poultry has been found from any other part of the country," Kumar said, adding that there was no apprehension of the virus affecting human beings. "It (bird flu) is localised in one state and certain parts of one state. We have requested the state government to undertake culling expeditiously," he said.

A total of 11,425 poultry birds were culled on Wednesday in the districts of Birbhum and South Dinajpur.

Though the West Bengal government maintained that 26,000 birds have been culled in bird flu-hit districts of Birbhum and Dakshin Dinajpur, figures available indicate only over 4,500 have been slaughtered.

Meanwhile, confusion prevailed over the culling operations with authorities in West Bengal unable to give the figure for today, but maintaining that 26 teams were on the job and the target was 26,000 birds.

Kumar said the West Bengal government had informed the Centre that the culling operations would be completed in 5-6 days. A total of 58 Rapid Response Teams in Birbhum and 26 in South Dinajpur are carrying out culling operations. Apart from poultry birds, at least 5,877 eggs and 1,218 kg of poultry feed was destroyed.

The West Bengal government has set a target of culling 3.76 lakh birds.Many poultry owners in Birbhum had sent their birds for sale outside the affected area, despite there being a ban on movement of poultry, reports from the districts said.

In Dakshin Dinajpur too, chicken were being sold on the outskirts of Balurghat, the district headquarters.

Blood samples from some dead chicken found in Jharkhand's Pakur district have been sent to the Regional Diseases Diagnostic Laboratory to ascertain the exact cause of the deaths.

Anisur Rehman denied delay on part of the West Bengal government in informing the Centre about the bird flu outbreak.

"It is absolutely baseless that we delayed intimating the Union Health Ministry. Rather, we took concrete steps but there has to be mass awareness to supplement our efforts," he said.

On reports of inadequate compensation to those whose chicken were culled, Kumar said "compensation is not a replacement cost".

"We have no request pending from the West Bengal government for more compensation," he said. The Centre and the state government share equal cost in the compensation package being provided.

In Birbhum, Rampurhat-II panchayet Samiti chairman Zakir Hussain said people were reluctant to give their birds for culling and were demanding cash instead of the official receipts being given to them for compensation.