There were differing versions on how the incident took place.
Sabarimala shrine spokesman Rahul Eeshwar said the tragedy occured at around 8.15 pm when two buses carrying the pilgrims collided and fell into a trench.
While Sabarimala Special Commissioner Rajendra Nair said a jeep had ploughed through the pilgrims, who were returning from 'makara samkrama pooja', using a narrow trekking path in a forest, about 7km from Sabarimala hilltop shrine.
Nair said there was a stampede after the jeep ran into the devotees. However, Eeshwar said there was no stampede but there was panic after the accident.