The pilgrims hailed from Mau, Sultanpur and Faizabad districts in Uttar Pradesh, police said adding the accident happened on Pilibhit-Basti highway near Chahmalpur village.
The private bus was carrying 58 passengers who were on pilgrimage to Ajmer Sharif, they said.
The bus stopped at a roadside eatery and a 10-year-old boy climbed atop the vehicle and touched an overhead electric wire, police said.
As a result, the bus also came in contact with the high-tension wire resulting in burn injuries to at least 40 pilgrims.
