Nearly 50,000 birds are to be culled in the areas surrounding two parts of West Bengal's Murshidabad district from where there have been reports of a fresh attack of avian flu. The culling operations that began on Monday will continue till March 12, Minister for Animal Resources Development Anisur Rahaman told The Hindu here. In all, more than 300 chickens are reported to have died from the disease in the two blocks of the affected district. 3-month ban There will be a ban on the sale and movement of poultry birds within a 5 km distance from the areas for three months as a precautionary measure, the Minister said.