HOUSTON -- Law enforcement officers cracked down on underage prostitutes in 29 cities, including Houston, KPRC Local 2 reported.

"These are not prostitutes, these are child sex victims," said Special Agent Patrick Fransen with the Houston FBI.

In the sting, undercover officers made more than 500 arrests nationwide.

"We go out and make as many arrests as we can," said Fransen. "Then we look for the underage victims."

In Houston, out of 45 arrests officials found that three of the suspected prostitutes were under the age of 18.

"This child is abused 10 to 15 times a night by various strangers and criminals," said Fransen.

Two of the ones found on Houston streets are each just 15 years old. Investigators said they'd been turning tricks for two years.

Investigators said pimps forced the girls into prostituion.

"Lots of times these kids have low self-esteem and are looking for someone to love and accept them," said Officer Emma Rodriguez with Houston Police Juvenile Sex Crimes.

Detectives said they also arrested a total of seven suspected pimps in Houston.

Another 17-year-old was arrested at a gentleman's club, Houston Dolls, in north Houston.

The club's general manager said he had no idea she was underage.

"I guess she had a fake ID, and that's our fault. We should have checked," said Jamaal Jackson. "I don't advocate hiring underage women."

Investigators said they are trying to figure out if the girl had a pimp, forcing her to work there to earn more money.

"Those three are the tip of the iceberg here in Houston," said Fransen.