Enraged over the foiled attempt, the accused set the victim ablaze, police said.
As the neighbours rushed on hearing the alarm, the youth fled the scene, police said, adding that the girl was rushed to Lohia hospital here with 80 per cent burn injuries. She was later referred to Safai Mini PGI.
A case has been registered on the complaint of the father of the girl and efforts were on to arrest the youth, said SP, Nilabdh Chaudhary.
The police has taken the youth's uncle into custody for questioning.
The victim's condition was serious, said Dr B.B Pushkar, at the Lohia hospital.