The incident took place at around 3 AM near Pukhrayan, about 100 kms from here.
Northern Central Railways spokesperson Vijay Kumar said that doctors and senior railway officials have reached the spot. The cause of the derailment was not known immediately.
Though casualties are feared, there is no official confirmation so far.
Buses are pressed into service to help passengers complete their journey, Kumar said, adding that there are possibilities of casualties in the S2 coach which is severely damaged.
Meanwhile, DIG (Kanpur range) Rajesh Modak said that two bogies of the train have been severely damaged and many people are feared dead.