Arun Singh and his associate, both students, allegedly passed lewd comments and outraged the modesty of a woman who was travelling in the Metro with her in-laws, police said.
The woman was travelling from Central to Dumdum Metro station when the incident happened inside a compartment and they were warned by her accompanying father-in-law.
As the two started harassing the woman again after getting down, the father-in-law, who is also a Metro Railways official, stopped the duo from fleeing and handed them over to the GRP. They were taken to the custody of city police later on.
The incident happened close on the heels of a young woman falling from train at Belur station to escape from molesters. She is currently recuperating.