Patna: The Gaya police have launched an investigation to ascertain the identity of a group of youths allegedly involved in thrashing a young girl and her fiancé at an isolated place recently.

The police swung into action after a video showing the girl and her friend being assaulted by youths went viral on social networking sites on Friday. Gaya senior superintendent of police (SSP) Rajiv Mishra said he has asked his subordinates to lodge a complaint on the basis of the video and initiate investigation.

Mishra said the police would leave no stone unturned to bring the culprits to book. "Efforts are on to ascertain the identity of the tormentors on the basis of the video clip that was provided to the police yesterday," he said, adding that the district police have taken a serious view of the matter.

"It is not clear where and when the incident happened with the victims. We have sought the help of the people's representatives, chaukidars, social activists and others to identity the tormentors, " he said, adding that any lapse on the part of the investigating officers wouldn't be tolerated.

In May this year, a zero FIR was lodged with the Gaya Kotwali police station in connection with alleged molestation of a teenage girl. The perpetrators of the crime also attempted to disrobe the girl and beat her up mercilessly when she resisted. The youth, who was accompanying him, was also not spared.

The Gaya police had lodged a complaint on the directive of inspector-general (Patna zone) N.H. Khan. The dialect used in the video was of Magadh region, which suggested that the offenders were of the region. Two suspects were also detained by the Kotwali police for interrogation.

Another video showing four men gang-raping a girl had gone viral in Jehanabad. In the video the victim is seen begging to leave her. This prompted the police to initiate action against the offenders, who were later arrested and sent to judicial custody. Within a few weeks, another video depicting some youths trying to disrobe a woman went viral on social media in Patna rural.

What came as a relief was that in all the cases, the accused were nabbed and sent to judicial custody. Inspector-general (Patna zone) Nayyar Hasnain Khan said the police submitted chargesheet against the accused in the respective courts after collecting clinching evidence.

"We are also thinking over initiating concrete steps to minimise such incidents," he told The Telegraph over phone.