Katwa SDPO Dhrubajyoti Das said that a police team from Ketugram police station picked up the duo from their residences on a tip-off.
The duo had boarded the Ahmedpur-Katwa narrow gauge passenger train posing as passengers, held the guard of the train hostage and forced the driver to stop the train near Pachundi at Katwa before committing the crimes.
The two were produced today in the Katwa sub-divisional court.
Two days after the incident, West Bengal chief minister Mamata Banerjee had said at the state secretariat that there was no evidence of rape in the medical report of the victim and that the CPI(M) had conspired to fabricate the story.