TAIPEI (Taiwan News) — New Taipei prosecutors said they have uncovered cases of underage girls being lured into sex work by gangs on Sunday (Nov. 12).

Prosecutors said that a division of the Bamboo Union gang was using a tattoo shop in New Taipei’s Sanxia District to coerce underage girls into sex work. A dozen people were arrested in connection with the case, and six are now under suspicion of various crimes after interrogations, per CNA.

The arrests follow police searches in 11 locations throughout Sanxia and Taipei’s Wenshan District. Prosecutors said that girls that did not agree to engage in sex work for the gangs were physically abused, and sometimes held captive in the shop and forced to take sexually explicit photos.

Prosecutors said that the threats and use of violence meant the girls were too afraid to leave.

Five of those under suspicion of crimes including criminal collusion, kidnapping, robbery, and assault have been denied bail. Three underage suspects were released on bail and are awaiting hearings at juvenile court.