The incident took place on Sunday in Katha village, where the girl was allegedly raped by two men, who are brothers, belonging to the same village, Superintendent of Police Dinesh Kumar P said.
The girl's father, an employee of a private company, was at work while her mother had gone to a relative's house to celebrate 'Makar Sankranti' when the incident occurred, he said.
"Agonised by the trauma of the incident, the girl sprinkled kerosene on herself and set herself afire, after which she died," the SP said.
Meanwhile, the father of the deceased girl in his police complaint has alleged that when her daughter was setting herself on fire, his son tried to intervene and save her, but the accused injured him as well, the SP said.
The parents reported the case to the police yesterday and an FIR was subsequently registered, the police said.
A case has been registered against the accused under the Protection of Children from Sexual Offences Act (POCSO) Act, for committing rape, and prompting to commit suicide, they said.