More than 10 million devout Hindus seeking absolution from their sins took a dip in holy waters in northern India during a span of four hours on Wednesday, authorities said, as they braced for millions more to swarm the site of the Kumbh Mela.

The Hindu festival that turned deadly in northern India on Wednesday is a religious gathering with deep spiritual meaning for devotees who come by the millions to take a cleansing dip in waters they consider sacred.

Officials expect visitor count at Kumbh Mela to exceed 550-600 million, with 12 days left in the six-week event.

Who was Emperor Harshavardhan, who donated all his wealth at Kumbh every five years? It is said that he gave until his royal treasury was completely empty.

At least 30 people have been killed in a crush at the world's largest religious gathering, the Hindu festival Kumbh Mela in northern India, officials say. The incident took place early on Wednesday when devotees on the riverbanks in the city of Prayagraj were trampled by other pilgrims rushing to take part in a sacred day of ritual bathing.

India's Kumbh Mela festival attracts tens of millions of Hindu faithful to Prayagraj in northern Uttar Pradesh state, but footage of an elderly monk making an offering at a shrine that circulated online is unrelated.

A video spread online shows an annual stone-pelting ritual in northern India, contrary to claims by social media posts that presented it as Hindu pilgrims attacking each other at the Kumbh Mela mega-festival.

As the Amrit Snan began at the ongoing Maha Kumbh Mela on Maghi Purnima on Wednesday morning, lakhs of people reached the Triveni Sangam ghat in Prayagraj to take the holy dip on the special occasion.