SAN DIEGO -- Three girls forced into prostitution were rescued over the weekend in San Diego as part of a nationwide law enforcement operation, authorities announced Monday.

The crackdown, led by the FBI and the National Center for Missing and Exploited Children, also resulted in the arrest of nearly 700 people, including 60 suspected pimps, over the last three days, officials said.

"Child prostitution continues to be a significant problem in our country, as evidenced by the number of children rescued through the continued efforts of our crimes-against-children task forces," said Kevin Perkins, assistant director of the FBI's Criminal Investigative Division.

Taking part in the 36-city enforcement effort, dubbed "Operation Cross Country IV," were personnel from the Chula Vista, Escondido and San Diego police departments and San Diego County Sheriff's Department.

Nationwide, 52 minors were recovered.

The operation was a program of the Innocence Lost National Initiative, which has led to the recovery of nearly 900 children being exploited on the streets and the conviction of 510 perpetrators, according to the FBI.