Nisha Sata (34), with her baby in her arms, was about to get down at Netaji Bhawan station from a Dumdum-bound train when the incident occurred last evening.
"Her leg got trapped between the doors of the Metro. Passengers inside the train started shouting to drew attention of the driver and other Railway staff," a senior officer of Kolkata Police said.
Metro rail officials rushed to Sata's rescue, he said adding that the woman had minor injuries and was treated by the Metro Railway Doctor.