LOS ANGELES -

A three-day nationwide operation focusing on underage victims of prostitution -- including raids in Los Angeles, Orange and Riverside Counties -- resulted in about 150 arrests of alleged pimps and other suspects and the recovery of 105 sexually exploited children, the FBI announced today.

The sweep took place in 76 cities and was carried out by the FBI in partnership with local, state and federal law enforcement agencies, along with the National Center for Missing and Exploited Children.

``Child prostitution remains a persistent threat to children across America,'' said Ron Hosko, assistant director of the FBI's Criminal Investigative Division.

``This operation serves as a reminder that these abhorrent crimes can happen anywhere and that the FBI remains committed to stopping this cycle of victimization and holding the criminals who profit from this exploitation accountable,'' Hosko said.

Laura Eimiller, spokeswoman for the FBI in Los Angeles, said that two minors, aged 15 and 16, were rescued in the Los Angeles area and four alleged pimps were arrested.

``We pro-actively looked for victims of prostitution,'' along with local law enforcement agencies, she said. Federal agents track victims and victimizers several ways, most notably online, Eimiller said.

For many pimps, ``the preferred way of advertising children and women in general'' was online, she said. The nature of online advertising, she said, was that pimps could operate from anywhere and offer women for prostitution anywhere.

``In many cases, these prostitutes are minors,'' Eimiller said.

Rep. Karen Bass, D-Los Angeles, commended authorities on the operation.   ``Their efforts again highlight the dire need to focus our attention on preventing child sex trafficking here in the United States, where over time this has become a growing concern for too many local communities,'' said Bass, who is co-chair of the Congressional Caucus on Foster Youth.

``Of particular concern to me are the alarming statistics showing that far too many trafficking victims are either current or former foster youth,'' Bass said. ``In my hometown of Los Angeles, over 60 percent of child victims of trafficking either are or were foster youth, and we know that pimps are now targeting foster youth group homes as hubs to recruit vulnerable girls.''

The effort was part of the FBI's Innocence Lost National Initiative, and was the seventh -- and largest -- such enforcement action to date, Hosko said.

Since its creation in 2003, the Innocence Lost National Initiative has resulted in the identification and recovery of more than 2,700 children who have been sexually exploited.