The incident happened when the victim's mother had gone to buy milk leaving her daughter with the neighbour, they said.
When she returned, the girl's mother found her lying in a grievously injured condition, police said.
The victim was rushed to a local hospital from where she was referred to PGI in Rohtak.
The victim's family, however, alleged that the hospital authorities delayed treatment to the girl by more than an hour saying that a case has to be lodged with the police first.
Condemning the incident, Jain said the culprits would not be spared at any cost and directed the police to book the accused at the earliest.