The accident on the New Farakka Express (14003) that was on its from Malda in West Bengal to New Delhi took place in Harchandpur area of Rae Bareli district at 6.10 am, Uttar Pradesh Additional Director General (ADG), Law and Order, Anand Kumar said.
About 30-35 people received minor injuries, Kumar, who had put the toll at seven earlier in the day, said.
Confusion prevailed for hours among senior police and railway officials over the death toll and the number of coaches that had derailed. While initially the death toll was said to be six, then seven, it was finally fixed at five by early evening.
There was similar confusion over the number of coaches that had derailed. The railways said five coaches went off the tracks after earlier putting their number at nine.
According to railways officials, five people, including a one-year-old and a seven-year-old, were killed. All of them were from Bihar.
Ten women and six minors are among the injured, the officials said.
Four of the seriously injured are being treated at the trauma centre of Lucknow's King George Medical University and two at the city's Sanjay Gandhi Postgraduate Institute of Medical Sciences, UP government spokesperson Shrikant Sharma told reporters.
The other injured were taken to Rae Bareli, about 80 km from the state capital Lucknow, for treatment, officials said.
A special train, which was arranged for the stranded passengers, left Lucknow for New Delhi at 2.45 pm with 1,369 passengers on board, railway officials said, adding that they were given food packets to sustain them through the journey.
He said the UP government, railways and the National Disaster Response Force were ensuring all possible assistance at the site of the accident.
"I offer my deepest condolences to the families of the deceased and those injured in the accident near Rae Bareli. I am in touch with officials for relief work," Goyal tweeted.
The minister has ordered an enquiry to be conducted by the Commission of Railway Safety, Northern Circle.
The chief minister, who headed a cabinet meeting to condole the loss of lives, directed the director general of police, district magistrate, the superintendent of police, health authorities and the NDRF to provide all possible assistance for relief and rescue operations.
An NDRF team, comprising 40 personnel, and senior officials from the state and the railways, also reached the spot.
According to ADG Kumar, the reason for the derailment will be known after an Anti-Terrorism Squad is sent for an on-the-spot probe.
Emergency helpline numbers were set up at the Deen Dayal Upadhyaya junction, Mughalsarai, officials said.
All up and down lines on the route were blocked and officials suspect that the number of casualties may rise.
The investigation related to the derailment will be conducted by Chief Commissioner, Railway Safety, Shailesh Pathak, who also probed the derailment of the Puri-Haridwar Utkal Express last year in which 22 people died.
(This story has not been edited by Business Standard staff and is auto-generated from a syndicated feed.)