The state administration received confirmation late last night that several samples had tested positive for H5N1 virus in two villages of Murshidabad district.

Animal Resources Development minister Anisur Rahman said on Sunday that bird flu had been confirmed in Nayamukundpur in Raghunathgunge Block II and in Dohapara village, Jiagunge block.

“We will begin culling poultry in the affected spots from tomorrow. Nayamukundpur was one of the villages affected during the initial outbreak. It could be that villagers had hidden some birds during culling, from which the virus has spread again.”

Murshidabad District Magistrate Subir Kumar Bhadra told The Indian Express that 50,000 birds are likely to be culled starting tomorrow. The teams are being assembled. The entire exercise should take two to three days.

“Last week, there were unnatural deaths among poultry birds, following which, samples were sent to the Bhopal-based High Risk Animal Diseases Laboratory, he said. “They confirmed it was bird flu to the state government yesterday.”

Reports said several hundred birds had died over the past week in both villages — located around 300 km from Kolkata.

In the beginning of February, the state administration had breathed a sigh of relief following the culling exercise. In its report, the World Health Organisation (WHO) in its report had called the Bengal outbreak the worst among the three avian influenza episodes in India — Maharashtra, Manipur and West Bengal.

Recently, the culling in all 14 affected districts had been declared complete and the ban on sale and consumption of poultry products had been lifted.

Of the 19 human blood and serum samples sent to the Bhopal lab, all had tested negative for the virus. Nearly two million people stay in the affected areas.