At least 17 people were killed and many more injured in a stampede at India's Maha Kumbh festival, the world's largest religious gathering, a doctor at a government hospital said, as tens of thousands of pilgrims rushed to dip in sacred river waters during the Hindu event.

Nearly 40 bodies were brought to a hospital morgue near the site of a stampede at the Maha Kumbh festival in India's northern state of Uttar Pradesh, three police sources told Reuters.

The accident happened on Wednesday morning local time, as tens of millions of devotees gathered to bathe on the holiest day of the Maha Kumbh Mela pilgrimage. An official death toll has yet to be given.