The operation targeted the trafficking of children for prostitution
US authorities have rescued nearly 50 child prostitutes - some as young as 13 - in a nationwide operation against the trafficking of children for sex.
More than 570 suspects were arrested during the action, which took place over three nights.
FBI agents and local police forces were involved in the operations which spanned some 29 cities.
Officials say a 16-year-old girl who recruits children as prostitutes is being sought as a priority.
Special Agent Melissa Morrow, of Washington's FBI, said adult prostitutes who were among those arrested tipped authorities off about the girl.
"She is currently 16 and started when she was 13," Agent Morrow said.
"Now she is out there recruiting other juveniles as well," she said, adding that finding her was "at the top of our list", the Associated Press news agency reported.
Cycle of violence
The ages of teenage prostitutes rescued in Operation Cross Country III ranged from 13 to 17.
The FBI said 571 people were arrested on suspicion of the trafficking children for prostitution and solicitation.
"We continue to pursue those who exploit our nation's children," said FBI Director Robert S Mueller III.
"We may not be able to return their innocence but we can remove them from this cycle of abuse and violence."