The sisters were living in a rented house located in front of the school they studied at. According to the police, the three accused also lived in the same vicinity.
On Tuesday night, the trio intercepted the sisters, forcefully took them to a nearby house and raped them. They were in an inebriated condition, the police said.
The condition of one of the sisters worsened after the gang rape, following which she was admitted at a local hospital.
Meanwhile, the other sister identified two of the three youths and also revealed their names to the police.
However, no arrests have been made so far.