More than three times the permitted number of people attended a Hindu religious event in north India that culminated in a stampede, killing at least 121 people, authorities said on Wednesday, adding that most of the victims were women.

It was not immediately clear what sparked the panic, which erupted as the event drew to a close Tuesday, but authorities believe massive overcrowding, insufficient exits and bad weather may have contributed to the high death toll.

About 250,000 people had gathered in a large tent on a muddy field for the event in the Hathras district of Uttar Pradesh state, about 200 kilometres from the Indian capital, New Delhi, despite permission being granted only for 80,000, an initial police report showed.

The gathering was held amid sweltering heat and high humidity.

"Initial reports suggest that the closed enclosure of the tent led to suffocation, causing discomfort and panic among attendees," said senior police officer Shalabh Mathur.

As the preacher — Suraj Pal Singh, also known as "Bhole Baba" — descended from the stage, officials said, devotees inside the tent surged forward to touch him, causing chaos as volunteers struggled to intervene.

An initial report from police suggests that thousands of people then thronged toward the exit. Many also slipped on the muddy ground, causing them to fall and be crushed by the crowd.

Witnesses described a scene of utter chaos as a number of devotees ran after the preacher when he was leaving in his car.

Most of the deaths resulted from suffocation, said doctors at a district hospital treating several victims.

Among the dead were 112 women and seven children, while 31 were injured, according to state authorities.

WATCH | Many of the victims were women and children: 

Stampede at religious event kills more than 100 in India

More than 100 people were killed in a stampede at a religious gathering in India's state of Uttar Pradesh over the weekend. Officials say the commotion from overcrowding and extreme afternoon heat contributed to the stampede.

Some devotees ran toward open fields nearby to escape the stampede but fell in the path of the rest of the crowd, the official added.

Media reports said a group of devotees organized the event, but did not identify anyone. Police were trying to ascertain the whereabouts of the preacher, the ANI news agency said.

Among the dead was Ruby, 30, who had travelled more than 300 kilometres to attend, along with her father, Chedilal.

Describing the stampede, he told Reuters, "I heard terrifying screams from women and there were bodies piled up on the ground near the exit."

"I was scared, I ran away and started calling my daughter on the phone," Chedilal added.

After an agonizing night of hospital visits to locate his daughter, Chedilal said he finally found her body at the Hathras district hospital in the morning.

The state's chief minister, Yogi Adityanath, met some of the injured on Wednesday and inspected the site, which stands amid paddy fields beside a busy highway.

A day after the stampede, waste littered the spot, partly inundated by rainfall. Some bamboo poles and a banner plastered with a picture of the preacher offered mute evidence of the tragedy.