Five coaches — B-1, B-2, B-3, B-4 and pantry car — overturned in the derailment while seven other coaches — B-5 to B-10 and power car — got derailed at the station.
Three passengers died on the spot, another succumbed to injuries in a hospital later.
Home Minister Rajnath Singh said it was too early to blame the Maoists for the derailment of the Delhi-Dibrugarh Rajdhani in Bihar that left four persons dead.
Bihar Chief Minister Jitan Ram Manjhi ruled out the involvement of Maoists.
It said Mr. Modi is in touch with Railway Minister D.V. Sadananda Gowda, who has updated the Prime Minister on the relief work at the accident site.
Railway Minister D.V. Sadananda Gowda has announce ex-gratia of rupees 2 lakh for the family of each of the deceased, rupees one lakh for the grievously injured passengers and 20 thousand rupees for those with minor injuries.
Helplines have been set up to provide information to families of the victims and other passengers at Chapra, Samastipur, Hajipur, Sonpur, Barauni, Muzaffarpur, Lucknow, Varanasi, Balia, Guwahati, Dibrugarh, Tinsukia, Mariani, Dimapur, Lumding, New Coochbehar, New Jalpaiguri and Katihar.
Railway has ordered an enquiry to be conducted by Commissioner Railway Safety, Eastern Circle to ascertain the cause of derailment.