12 Kolkata: Multi-agency security drillsare scheduled to take place at 31 places in Bengal, 17 of them being slated for Chicken's Neck. Chicken's Neck or the Siliguri Corridor is a narrow strip of land, measuring about 22km-35km in width, serves as the sole land connection between mainland India and the Northeast.Several meetings have taken place between the Bengal govt security agencies, central forces manning the international borders in Bengal, central security agencies and Bureau of Civil Aviation.Chief minister Mamata Banerjee on Thursday also asked DGP Rajeev Kumar to step up vigil along the Bengal border. "We have to keep tabs on the border, so that none can enter with arms and ammunition. Train stations are also to be kept under vigil," the CM said.Chicken's Neck has been put on intense security radar, an officer said. In Bengal, the Union home ministry has designated 24 locations under Category 2 on security grade and seven under Category 3, depending on which the intensity of the drill will be carried out. "The drills will incorporate comprehensive security measures, including crash-blackout procedures, camouflage of vital installations and evacuation rehearsals," a senior civil defence officer told reporters on Thursday. "Our objective is to minimise civilian casualties while maintaining optimal preparedness for any contingency."