Police said the couple were admitted to the emergency ward of the district hospital.
The girl, Baby, 18, alleged that her husband Hira, 25, a resident of Moradabad, had thrown her off a speeding train on Tuesday evening, and then jumped off it himself, according to the police.
She told the police, "I used to receive calls from an unknown number for around three months. Eventually, I started talking to the caller Hira and then fell in love with him. We then decided to get married. On July 26, Hira reached Tinsukia and I eloped with him. We reached Patna the next day, stayed in a hotel for two days and got married in a temple on July 29."
Baby said that they boarded a Moradabad-bound train on Tuesday. The train had just crossed Bareilly when Hira threw her off. Hira was not in a condition to narrate his side of the story, but Baby insisted she had been thrown off the running train, after which her husband followed voluntarily.
She also said her father, Upendra Ram, was an employee of Tinsukia municipality.
SP (city) Abhinandan Singh said the GRP (Government Railway Police) had been instructed to probe the case, while the girl had been referred to Lucknow in a critical condition. Her parents have also been informed of the incident, he added.
( With inputs from IANS )