Police said on Monday that a 16-year-old girl was gang-raped and apparently thrown out of a moving train.
The incident happened in the eastern state of Bihar in India.
Regional police chief Ashok Kumar said that the teenager was abducted near her home in Lakhisarai district by a group of six youths on Friday.
Kumar said she was sexually assaulted at an isolated spot before she was forced into a train at a local station and found hours later on the tracks, injured and unconscious.
The girl’s family said she had been thrown off the train, a claim that police said it was investigating.
“The girl is being treated for serious injuries. We have arrested one of the suspects, a boy, in the case. Results of medial tests to confirm sexual assault are being awaited,” Kumar said.
Local media reports said the teen was in a critical condition and fighting for her life at a government hospital where she was being treated.
Bihar Chief Minister, Nitish Kumar, promised strong action against the accused.
Sexual violence has been a focus of public attention in India since the fatal gang rape of a student on a bus in New Delhi in December 2012.
Activists say little has changed in attitude towards sexual assault, and attacks on women continue unabated.