Multiple people were feared dead in a crowd crush at the world’s largest religious gathering in India on Wednesday, as tens of millions of devotees went to bathe in a river on one of the most sacred days of a Hindu festival.

More than seven people were killed in a stampede at the Maha Kumbh Mela, or Great Pitcher Festival, in the northern Indian holy city of Prayagraj on Wednesday.

Officials had been preparing for months for the world’s largest religious festival, with around 400 million Hindu pilgrims expected to take part