West Bengal Chief Minister Mamata Banerjee, also a former Railway Minister, questioned the figures, stating that 61 people from her state have died and 182 others are still missing.
Roy said of the 1,100 injured, less than 200 are undergoing treatment in various hospitals.
He said that of the 278 bodies, 177 have been identified while 101 more are yet to be identified and these unclaimed bodies have been kept in six different hospitals.
Roy said the Railways has deployed people in states such as Odisha, West Bengal, Jharkhand, Chhattisgarh, Bihar, Telangana, Andhra Pradesh and Tamil Nadu to locate any missing person.
He said the bodies will be preserved in a scientific manner.