The girl was crossing the Mahatma Gandhi Road when the auto-rickshaw hit her from behind and injuring her, the sources said.
The girl was rushed to the Medical College Hospital. The auto-rickshaw driver was arrested, they said.
On January 25, a 27-year-old woman was assaulted by an auto-rickshaw driver over change for a Rs 50 currency note near a petrol pump at Alipur.
Earlier on January 16, a woman executive was punched in the face and left bleeding by an auto-rickshaw driver at Park Circus.
The government has also decided to set up a helpline for passengers to register their complaints against them.
Auto-rickshaws, which are contract carriages, run illegally as state carriages on fixed routes without meters and charge fares arbitrarily.