Four people were arrested in Clayton County on child exploitation charges during a two-day sting, and more arrests are expected after electronic devices are reviewed, the GBI said Monday.

Investigators believe they also found two former victims of molestation, the agency said. Online tips prompted the two-month investigation, followed by days of tracking down the suspects, the GBI said.

Investigators executed 13 search warrants and previewed 57 digital devices, most of which were cellphones, the agency said.

“Investigators who work child exploitation investigations are increasingly seeing more mobile phones as the main instrument by which predators seek out child sexual abuse material and communicate with others who are like-minded,” the GBI said in an emailed statement.

Those arrested were Pedro Sanchez Campos, 22; Khaila Johnson, 24; Clifford Lamere, 60; and Ilan Dan Xula Osorio, 22. No further details were released about the crimes.