Charges include the forced prostitution of females under 18, rape, grooming and trafficking. 24 young women aged between 11 and 16 are believed to have been victimised over a six-year period.
The twelve men arrested are all aged between 21 and 37.
Det Supt Rob Mason of the Thames Valley Police told the press, "We believe we have uncovered an organised crime group who have been running a business of selling young girls for sex.
"We have also identified a number of customers who we have reason to believe have used this service. Our number one priority is to protect the victims, both their identities and wellbeing."
Supt Chris Sharp added, "Policing teams will be issuing information about the operation with contact details if people need further information, or would like to report any activity in relation to this investigation."
Neighbourhood police teams will be working in the area on reassurance patrols.
More information will be made available as the investigation continues.