Manipur Police has arrested a fifth person, aged around 19, in connection with the May 4 parading of two women naked in Kangpokpi district of the state, officials said on Saturday.
The two women are alleged to have been sexually assaulted before being set free.
A 26-second video of the horrific incident surfaced on Wednesday.
The next day, police made the first arrest in connection with the incident.
A man who was part of the mob that paraded the women at B Phainom village and was seen dragging one of them was nabbed.
Three more arrests were made later that day.
These four persons were remanded in 11-day police custody on Friday.
One of the women seen in the video is the wife of an ex-army man, who served as a subedar in the Assam Regiment and had even fought in the Kargil War.
A complaint in connection with the video was lodged on June 21 at Saikul police station in Kangpokpi district.
The FIR filed in this case, a copy of which has been accessed by PTI, revealed the tale of mayhem which occurred before the abduction of the tribal women.
The FIR also claimed that one person was killed by the mob as he tried to protect his sister from being raped on May 4 before the two were paraded naked and molested in front of others.
In a separate incident, a tribal woman had lodged a complaint at Saikul police station, stating that her 21-year-old daughter and her 24-year-old friend were allegedly raped by a mob at their rented house near Konung Mamang before brutally murdering them on May 4.
The woman said both of them were working as caretaker at a car washing station and their bodies are yet to be recovered.
Police has registered a case under various sections of Indian Penal Code including 153A (promoting enmity between different groups), 398(attempt to commit robbery), 436 (use of fire or explosives to destroy house) and 448 (house-tresspass) besides a section of Arms Act.
However, no charges of gang rape or murder are levelled in the FIR.
The zero FIR was registered on May 16 on a complaint by the mother of one of the victims at Saikul police station in Kangpopki district, 35 km away from the site of the incident.
She alleged that on May 4, her daughter and her friend were brutally murdered after being raped and tortured by unknown people, numbering 100 to 200, and allegedly belonging to the majority community.
The two girls were working at a car wash outlet and residing at a rented accommodation at Konung Mamang in Imphal East.
Their bodies, which are yet to be handed over to the family, are believed to be kept in a morgue at a hospital in Imphal valley where her family cannot visit because of ethnic clashes in the state since May 3. Over 160 people have died so far.
Police officials, speaking on condition of anonymity, said that since it was a zero FIR, other sections can be added once investigation of the case is taken up by the Porompat police station.
When a police station receives a complaint regarding a crime that has occurred outside its jurisdiction, it registers a zero FIR.
The charges filed in the Saikul police station include 153-A (promoting enmity between different groups), 397 and 398 (robbery or attempt to commit robbery or dacoity when armed with deadly weapon), 427 (mischief), 436 (mischief by fire or explosive substance with intent to destroy house), 448 (trespass), 34 (common intent) of the Indian Penal Code and section 25(1C) of the Arms Act (possessing prohibited weapons).
More than 160 people have lost their lives, and several have been injured since ethnic violence broke out in the state on May 3, when a 'Tribal Solidarity March' was organised in the hill districts to protest against the Meitei community's demand for Scheduled Tribe (ST) status.
Meiteis account for about 53 per cent of Manipur's population and live mostly in the Imphal Valley, while tribals, which include Nagas and Kukis, constitute 40 per cent and reside mostly in the hill districts.
