Raids in more than 70 cities across the United States have resulted in the arrest of 150 "pimps" and other individuals and the rescue of 105 sexually exploited children, the FBI said.

"It was the FBI’s largest action to date focusing on the recovery of sexually exploited children, and took law enforcement agencies to streets, motels, casinos and social media platforms", Ronald Hosko, the assistant director of the FBI's criminal investigative division, said on Monday.

The youngest child was 13 years old, the agency said.

Criminal charges against the 150 will include human trafficking, authorities said.

'Co-ordinated offensive'

Al Jazeera’s Alan Fisher, reporting from Washington, said the operation was one of the biggest of its kind.

"This is being described as a coordinated offensive across the US,” our correspondent said.

“They have arrested more than 150 people for the exploitation of children and adults. Of the children rescued, they are now in the hands of child protective services across US."

An estimated 240,000 children in the US are considered at risk of sexual exploitation.

Hosko said he hoped the the investigation would focus attention on sex trafficking, “this threat that robs us of our children”.

Operation Cross Country - a three-day nationwide enforcement action focusing on underage victims of prostitution - took place in 76 cities and was carried out by the FBI in partnership with local, state, and federal law enforcement agencies, and the National Center for Missing and Exploited Children (NCMEC) as part of the Bureau’s Innocence Lost National Initiative.

Since its creation in 2003, the Innocence Lost National Initiative has resulted in the identification and recovery of 2,700 children who have been sexually exploited, and the substantial sentences of convicted pimps, including eight federal life sentences and terms of imprisonment frequently ranging from 15-50 years, according to the FBI statement.

Source: Al Jazeera and agencies