Kumbh Mela: World's largest religious festival

More than 20 million Hindu pilgrims ritually bathed in India's holy rivers on the opening day of the Kumbh Mela, a gigantic festival billed as the world's largest human gathering.

The spectacular seven-week festival began Tuesday in Allahabad, an ancient city that rises alongside the Ganges, Yamuna and mythical Saraswati rivers in northern Uttar Pradesh state.

The meeting point of these rivers is considered among the holiest places in Hinduism and devotees believe bathing there during the Kumbh helps cleanse sins and brings salvation.

The Kumbh attracts astonishing numbers of visitors, outstripping the Haj pilgrimage to Mecca or any other large-scale gathering. Kumbh organisers say the last major gathering in Allahabad in 2013 drew 120 million people -- nearly the population of Japan.

A gigantic tent city has emerged near the banks of the hallowed rivers with a 45-square kilometre encampment set aside specially for pilgrims.

The Kumbh, which runs until March 4, was recognised as an intangible cultural heritage by UNESCO in 2017.