The incident took place at Ramnagar area late last night when the pilgrims, hailing from Sitapur, were returning after attending 'naag devta (snake God)' mela in Satrikh area.
Four children, aged between 10 and 16, died on the spot, police said.
Of the 61 injured, four were rushed to Lucknow Trauma centre, while the others were admitted to the district hospital.
In another accident, eight people were injured when a private bus, on way to Mumbai from Siddhartnagar, overturned at Asandra area, police said.