Hundreds of people have been arrested and 21 children rescued in what the FBI is calling a five-day roundup of networks of pimps who force children into prostitution. The Justice Department says it targeted 16 cities as part of its "Operation Cross Country" that caps off five years of similar stings nationwide.

In all, authorities arrested 345 people — including 290 adult prostitutes — during the operation that ended this week. Since 2003, 308 pimps and hookers have been convicted in state and federal courts of forcing youngsters into prostitution, and 433 child victims have been rescued, Mueller said. The cities targeted in this week's sting are: Atlanta; Boston; Dallas; Detroit; Houston; Las Vegas; Los Angeles; Miami; Montgomery County, Md.; Oakland, Calif.; Phoenix; Reno, Nev.; Sacramento, Calif.; Tampa; Toledo, Ohio and Washington.