With parts of West Bengal in the throes of the avian flu, the government has stepped up its efforts to ensure that the disease does not spread further.

The Central Board of Excise and Customs (CBEC) has issued fresh instructions to its customs field formations, directing them to keep a close check on livestock and poultry coming in from neighbouring countries, especially Bangladesh.

?Cross-border movement of poultry and poultry products needs to be monitored especially in the region bordering Bangladesh, where avian influenza has been reported over the past 10 months,? the CBEC has instructed.

Bird flu has also been detected in Malda, West Bengal, which is along the border of Bangladesh. The CBEC has asked field formations to be remain vigilant on international movement of poultry and poultry products at the border.

To arrest further spread of the flu, West Bengal has already sealed its borders with Bangladesh, Bhutan and Nepal.

The CBEC had issued similar instructions earlier in 2005 and 2007 with the outbreaks of the fatal flu. It had then laid out detailed procedures for clearance of livestock and livestock products by customs officials, which are also to be followed now.

Bird flu reappeared in the country affecting parts of West Bengal with official confirmation on January 15. About seven districts of the state?Birbhum, Murshidabad, South Dinajpur, Burdwan, Nadia, Bankura and Malda- have been affected by the disease.