Two Dalit sisters were allegedly gang raped by three men after being held captive in a village in Uttar Pradesh's Ayodhya district.
The victims, one of whom is a minor, have been sent for a medical examination, the police said.
The incident took place when the sisters were reportedly returning from Sherpurpura market near their village under the Bikapur police station.
The three accused held them captive and allegedly outraged their modesty after taking them to a sugarcane field.
They threatened the victims of dire consequences and fled.
Pramod Kumar Yadav, circle officer, Bikapur, said that an extensive search has been launched to locate the accused.
The two girls informed their family members about the incident a day after their return, after which a written application was submitted to the police.
Initially, some local cops tried to hush up the matter, but later registered the FIR after intervention of some senior police officials, according to the victim's father.
The FIR has been lodged against one Bhai Lal Yadav, Tribhuvan Yadav and an unidentified person under Indian Penal Code sections 376-D (gang rape), 323 (voluntarily causing hurt), 504 (insulting) and 506 (criminal intimidation).
The circle officer said charges under atrocities against Dalits and Protection of Children from Sexual Offences were also slapped against the accused persons.