Religious event draws millions to Ganges Millions of pilgrims bathed in the River Ganges on Monday at the start of a two-month Hindu religious gathering called the Kumbh Mela, reputed to bring together the largest crowds on earth. Naked sadhus or holy men, smeared with ash and clad only in garlands of marigolds, plunged into the chilly waters at the confluence of the Yamuna and Ganges rivers at dawn, followed by devout Indians from across this country of 1.2bn people. Organisers in Allahabad said 10m pilgrims were expected to have bathed by the end of the day, while even greater numbers are likely to attend on other auspicious days over the two-month duration of the festival, which occurs on this scale once every 12 years. Roughly 40m pilgrims gathered on the main bathing day in 2001. This time, the total number of visitors - mostly Indians with a smattering of curious or spiritually minded foreigners - could reach more than 100m by the time by the event draws to a close on March 10. Devout Hindus believe the waters of the Ganges wash away sins, and are undeterred by the hordes of their fellow-pilgrims, difficulties with congested trains and buses or by any fear of disease from a river now contaminated with sewage and industrial waste. While the Kumbh Mela provides more than 600,000 jobs and other economic advantages for the impoverished state of Uttar Pradesh, it also presents the state government with extraordinary logistical challenges made more daunting by India's increasing population. During the 1954 Kumbh Mela, hundreds of pilgrims were trampled to death and drowned as a result of a stampede, and the authorities now go to great lengths to try to control the movements of the devotees as well as to ensure adequate sanitation, deploying 30,000 police officers and providing 40,000 toilets. Upstream, dam operators have been instructed to release sufficient water for the ceremonies while factory owners have been told not to disgorge toxic waste into the river. The Kumbh Mela dates back many centuries and is rooted in Hindu mythology: as gods and demons fought over a jug of nectar, it spilled on to four sites along the Ganges now considered holy, including this year's location at Allahabad. Every year the Mela is vast. On the 12th year, as in 2013, the size is almost unimaginable. This is the Kumbh Mela," says a report by a social science research group from British and Indian universities that has studied the phenomenon. They concluded that although the Mela was a noisy ordeal for pilgrims, they were so happy to be taking part that "participation at the Mela actually increases people's mental and physical wellbeing."