The seven members of a Bali teenage motorcycle gang accused her of flirting with a gang member's boyfriend.
The all-girl gang allegedly took the victim, 15-year-old Kiki Ariani, to a secluded spot and assaulted her.
The attack was filmed by a gang member and posted on video-sharing website YouTube.
The 51/2-minute clip quickly went viral, Jakarta Globe reported.
The person who uploaded it claimed that it was done to embarrass the victim.
All the seven members of the Cewek Macho Performance (or Macho Girls Performance) gang have been arrested.
Five have been charged with assaulting the teenager and two are being questioned to find out their exact role in the assault, said Denpasar Police chief Comr. Arif Sugiarto.
The girls are all 16 or 17 years old, the police chief said.
The footage shows assailants ripping Kiki's clothes and trying to smash a bottle against her head.
Some of them are seen pulling her hair. Kiki is seen being pushed to the ground.
Speaking at her Denpasar home, Kiki said the beating occurred in December in the Balinese capital Denpasar.
She told Jakarta Globe: "They picked me up at my home and I was taken to an empty lot.
"They accused me of different things - flirting with Okta's (a gang member) boyfriend, getting my club jacket dirty, stealing money from the group.
"But before I got to explain anything, they beat me and kicked me."
Kiki said she joined the gang and stayed in it for a year because she had a lot in common with the other members.
Like others in the group, she comes from a broken home, dropped out of school and loves motorcycles.
Kiki, who moved in with her aunt after her father remarried, said she didn't finish elementary school.
She said that after the video caused an uproar, her attackers apologised to her.
But other people urged Kiki to file a police report, which she eventually did.
Ms Titik Suhariyanti of the Bali Child Protection Agency said the investigation must continue to deter others from conducting similar attacks.
