Prayagraj, Jan 15 (IANS): Thousands of devotees took a holy dip here at the Sangam -- the confluence of the Ganga and Yamuna and the mystical Saraswati rivers -- on Tuesday morning, on the auspicious occasion of Makar Sankranti and marking the onset of the Kumbh Mela.

Prime Minister Narendra Modi urged devotees to participate in the Kumbh Mela, which is organised at a much wider scale this year than its previous editions, to witness India's spiritual, cultural and social diversities.

Elaborate security arrangements were in place and pontoon bridges have been constructed to lead the visitors to the 5-km bathing ghat at Sangam.

Security personnel have been deployed at all entry and exit points of these bridges to maintain law and order.

Soon after midnight, throngs of devotees who have gathered here for the fair from within the country and abroad, began proceeding towards the bathing ghats. Loud religious chantings as well as melodious singing of 'bhajans' reverberated through the by-lanes of the city for most of the night.

In an absolute electrifying setting, visitors reached the ghats that were lit up like Diwali in a hue of multiple colours, amid heightened security and waited for the "Shahi Snan" (royal bath) to begin.

The moment arrived just before dawn when, with prayers in their breath, the visitors took the holy dip in the water as cold as ice.

About 13 'akharas' will be participating in the "Shahi Snan" on Tuesday with each being allocated about 45 minutes by the Kumbh authorities. The ceremonial bath is drawing huge crowds as devotees continue to arrive here in large numbers.

Prime Minister Modi posted a video on Twitter shortly after the "Shahi Snan" ceremony began, marking the official beginning of the fair.

The "Shahi Snan" is considered among the most significant components of the Kumbh Mela, and is supposed to begin at a certain hour.

The Kumbh Mela is held every six years, while the Maha Kumbh takes place every 12 years.

According to officials, about 15 crore devotees are expected to partake in the pilgrimage, which, according to legends, opens the doors to heaven.

Over 40,000 LED lights have been used by the administration to light up the bathing ghats as well as illuminate the historic city.

The Kumbh Mela will reach its culmination on March 4, which alo marks the Maha Shivratri, the last of the six dates for "Shahi Snan".