Updated

The FBI, working alongside state and local authorities across the U.S., rescued 79 minors being held as sex slaves, the agency announced Monday.

The minors – two of whom were boys, the rest girls – were taken from 57 different cities during “Operation Cross Country” raids on Thursday, Friday and Saturday.

The youngest kid was 13, while another told of being held as a sex slave since age 11, said Kevin Perkins, the head of the FBI’s criminal division.

Pimps were luring the kids through social media, targeting ones who came from “dysfunctional” families and offering them gifts, Perkins told Fox News.

If the minors tried to leave the operation, the pimps would threaten them and tell them their parents would be killed.

"They basically go into survival mode,” Perkins said, explaining how the kids would do anything to eat.

“Operation Cross Country” began in 2008, with the latest roundup of sex slaves the biggest yet, FBI spokesman Mike Kortan said.

Fox News’ Mike Levine contributed to this report.