The incident took place in Jodhpur-Howrah Express yesterday morning, soon after the train departed from Tundla station, they said.
The robbers entered the general compartment of the train and snatched items like cash, jewellery, mobile phones and other valuables. They also attacked the passengers who resisted.
When the train reached Kanpur, the aggrieved passengers lodged their FIR and were provided first-aid, they said, adding that the matter has been referred to railway police in Firozabad.