The incident was reported from east Delhi's Kondli area.
The deceased, identified as Dhanlakshmi, was attacked by the dog Tuesday evening.
The victim's mother, Chitra Gupta told police that Ravi Solanki, who lives in her neighbourhood, had taken her daughter out on the pretext of playing with her. Meanwhile, another neighbour Rajat who was roaming in the area along with his dog approached Ravi and the baby.
"Rajat unleashed his dog on Ravi to frighten him. However, the dog attacked the girl. It kept dragging the girl on the street. Residents managed to rescue the girl from the dog's clutches and rushed her to a nearby hospital where she succumbed to her injuries," said a police officer.
The official further said that a case regarding the incident has been registered and Rajat will be arrested soon.