The stampede reportedly unfolded after a preacher's speech as a religious event known as "Satsang" was ending and everyone was leaving the venue.
Suffocation at the venue is believed to have caused discomfort among the event participants, who started to run causing the stampede, the Uttar Pradesh police said, adding that it was hot and humid during the event.
"There was a huge crowd gathered of followers at the spot. There was no way out, and everybody fell on each other, and a stampede took place. When I tried to move out, there were motorcycles parked outside, which blocked my way. Many fainted while others died," one of the witnesses was quoted as saying by the newspaper.
Uttar Pradesh Chief Minister Yogi Adityanath expressed grief over the tragic events and ordered an investigation into the matter.