MOSCOW, October 27 (RIA Novosti) - FBI officials in the U.S. rescued 52 children and arrested about 700 people, including 60 suspected pimps, in a three-day nationwide crackdown on child prostitution, American media said on Tuesday.

The operation, which concluded on Monday, was held in 36 cities across the country, with almost 1,600 FBI agents, police officers and representatives of the National Center for Missing and Exploited Children involved, the Los Angeles Times reported.

Media reports said most of the rescued children were girls under 18, with the youngest just 10 years old.

The operation was part of the Innocence Lost National Initiative, started in the country in 2003 to address child sex trafficking. According to the FBI, about 900 children have been released, some 510 people were convicted and $3.1 million in assets were seized as the result of the operation, papers said.

The Boston Herald website quoted Ernie Allen, president of the National Center for Missing and Exploited Children, as saying the arrests were "extraordinary, almost historic."

"It's an incredible model. I think its working. We're having an enormous impact on this business," he said.

Though, he said that 100,000 children are still involved in sex trafficking in the U.S., adding that the problem is growing partly because of the recession.