An estimated five lakh pilgrims are expected to take the holy dip at the confluence of the Ganga and the Bay of Bengal at Sagar Island on Makar Sankranti on Thursday when the Ganga Sagar Mela also begins. According to the almanac the most auspicious time for the holy dip is between between 4:47 AM and 3:30 PM on January 15. So far, over one lakh fifty thousand pilgrims have arrived from different parts of the country to Sagar Island in South 24 Parganas district of West Bengal.District Magistrate N S Nigam said that though there was no threat perception, the administration will not take any chances and adequate security measures have been taken. An 8,000-strong police force, the Bomb Squad, sniffer dogs have been deployed with civil defence personnel patrolling the waters in speedboats. Coast Guard and naval vessels were also patrolling the waters.