It’s late evening in the city of Prayagraj and the roadside vendors selling snacks are packing up their wares to shut for the night.

Vast crowds of Hindu pilgrims in India bathed in sacred waters as the Kumbh Mela festival opened on Monday, with organisers expecting 400 million people -- the world's largest gathering of humanity -- to assemble over six weeks.India is the world's most populous nation, with 1.4 billion people, and so is used to large crowds.

Nearly 15 million Hindus, six times the number expected, took a dip in freezing waters seeking absolution of their sins on Monday, the first day of India's festival that could draw the world's largest single gathering of humanity.

Hindu devotees gather for a dip at the confluence of the Ganges, the Yamuna and the mythical Saraswati rivers on the first day of the 45-day-long Maha Kumbh festival in Prayagraj, India, Monday, Jan.

Hari Om, a devotional OTT platform, offers free subscriptions at the Maha Kumbh Mela 2025. This spiritual gathering in Prayagraj highlights India's cultural heritage, drawing millions of devotees. Hari Om aims to blend tradition with modernity through its extensive devotional content available for free to attendees.

In the wake of this winter flu season, the holding of mass gathering, such as Kumbh Mela, may pose health risks. Maha Kumbh has been a case of study among health experts for a long time. Here's what studies and research have to say about health challenges at Maha Kumbh.