A teenager from Bengal was allegedly gang-raped in a military compartment of the Howrah-Amritsar Express on Sunday.
An army jawan, identified as Majrish Tripathi, 26, has been arrested in this connection.
The 16-year-old girl, whose father works in the excise department of Bengal, alleged that three men had forced her to drink and two of them of raped her inside the toilet of the compartment.
The girl, a resident of Dum Dum, went missing around 5am on Sunday. Her parents lodged a missing report with a voluntary outfit, Childline, along with her photograph.
Childline, Howrah, shared her picture on its WhatsApp group. Childline, Madhupur, close to Deoghar in Jharkhand, alerted the Government Railway Police. Two search teams were sent to Madhupur and Jasidih stations.
"Around 8.30pm, when the train reached Madhupur, we began searching the compartments," said inspector Fazal Ahmad.
"In the army coach, we found the girl, lying on a berth, barely conscious. A jawan was offering her snacks. We took both in custody. Initially, we thought the girl had eloped with the jawan.
"But on regaining sense, she said she had boarded the army compartment by mistake at Howrah.
"As soon as the train left the station at 1.50pm, she said three jawans, including the one whom we had taken in custody, began harassing her."
Ahmad said the girl had alleged that the three had forced her to drink.
"They followed her into the toilet where two of them raped her. Since she was intoxicated she could not raise the alarm. She said they had threatened to throw her off the train if she spoke about the rape to anyone," the officer said.