Hundreds of thousands of Hindu pilgrims led by naked, ash-covered holy men streamed into the sacred river Ganges on Monday at the start of the world's biggest religious festival.

The Kumbh Mela in the Indian town of Allahabad will see up to 100 million worshippers gather over the next 55 days to take a ritual bath in the holy waters, believed to cleanse sins and bestow blessings.

Before daybreak on Monday, a day chosen by astrologers as auspicious, hundreds of gurus, some brandishing swords and tridents, ran into the freezing waters for the first bath, signaling the start of events.

Assorted dreadlocked holy men, seers and self-proclaimed saints from all over the country have assembled for the colorful and chaotic spectacle that offers a rare glimpse of the dizzying range of Indian spiritualism.

For most ordinary Indians, the Kumbh Mela is a religious holiday enjoyed in an almost carnival atmosphere, where prayers and blessings are offered and sought alongside family or friends camping together at the vast festival site.

The hardships of being squeezed in the crowds, enduring endless whistling and barked orders from thousands of policemen and even catching a cold in the chilly January weather are seen as a price worth paying for a dip.

The Kumbh Mela takes place every 12 years in Allahabad, in northern Uttar Pradesh state, with smaller but similar events every three years in other locations around India.

It has its origins in Hindu mythology, which describes how a few drops of the nectar of immortality fell on the four places that host the festival- Allahabad, Nasik, Ujjain and Haridwar.

The "Mother Ganges" is worshipped as a god and is seen as both the giver and taker of life. Most devotees dunk their heads under the water, some drink it and others bottle it and take it home as gifts.

Police expect 250,000 people on Monday with 20 million anticipated on February 15, the most auspicious day. Overall, organizers are counting on about 100 million coming.

AFP