FBI officials say they have rescued 52 children in a series of raids around the country aimed at underage prostitution.

Authorities say the youngest victim was just 10 years old. The bureau and local police officials also arrested 60 pimps during the three-day enforcement effort in 36 cities.

The raids are the latest in a long-running Operation Cross Country aimed at child prostitution rings around the country. Almost 1,600 agents and officers took part in the raids, which led to federal and state charges against a total of 691 suspects. The investigations typically target places where minors are likely to be sold for sex, including truck stops, casinos, public streets, and internet websites.