Moments before a deadly stampede at the world's biggest religious gathering in India, Hindu devotees queuing to take a spiritual bath in a river said they pleaded with police to open barricaded routes to thin out a surging crowd.

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.

Many were feared dead after millions of Hindu pilgrims at a huge Hindu festival in India rushed to bathe in holy river waters.