The incident was reported from the Chandni Mahal area at 11 am on Tuesday.
Police said an alert caretaker at the gate of the nursery school prevented the woman from taking away Insha and Aman. The two girls are from Kucha Kalan in Old Delhi.
“She told the caretaker at the gate that they were her daughters. But as soon as she picked them up in her arms, the children started crying. That alarmed the caretaker and she stopped the woman. She also alerted the school staff and police about it,” Additional Commissioner of Police (Central) Devesh Srivastava said.
Police later found that the woman, a resident of Dilshad Garden, has been undergoing treatment in Institute of Human Behaviour & Allied Sciences (IHBAS).
“We cannot disclose her name. A case of kidnapping has been registered at Chandni Mahal police station,” an officer said.