Millions of Hindu devotees, mystics and holy men and women from all across India flocked to the northern city of Prayagraj on Monday to kickstart what is being touted as the world’s largest religious gathering.

India's Maha Kumbh Mela, or Great Pitcher Festival, is set to be the world's largest gathering of humanity, with 400 million visitors expected at the six-week event that began this week in the northern city of Prayagraj.

PRAYAGRAJ: Naked Hindu ascetics smeared in holy ash charged into the waters of “sacred rivers” in India on Tuesday, part of a large crowd of 35 million devotees who took the holy dip on the second day of the Maha Kumbh Mela, or Great Pitcher Festival, seeking absolution from their sins.