The girl has been admitted to the Cooper Hospital, where her condition is reportedly serious.
The girl has given her statement to the police based on which one person has been arrested.
Medical tests have been conducted on the four-year-old and reports are awaited.
The incident comes days after the gang-rape of a woman photojournalist in the city, which is considered safe for women. The five accused men, who assaulted the woman photojournalist, have been arrested.