More than 400 U.S. military service members were tricked into believing they possessed child porn and surrendered more than $560,000 in order to avoid charges as part of a plot conducted by South Carolina inmates.

"With nothing more than smart phones and a few keystrokes, South Carolina inmates along with outside accomplices victimized hundreds of people," Daniel Andrews, director of the Computer Crime Investigative Unit of the U.S. Army Criminal Investigation Command, announced on Wednesday.

According to the Naval Criminal Investigative Service, South Carolina inmates established fabricated online female personas on social media forums and online dating website and then singled out 442 service members from the Navy, Army, Air Force, and Marine Corps to extort them for money.

The inmates then pretended to step in as either the father of the female or police officers and claim that the female was a minor after the service members responded to the photos and requested money for the family to prevent them from pressing charges for obtaining child pornography, NCIS said.

Arrest warrants had been executed and summonses served by agents from military criminal investigative organizations for money laundering, extortion, and wire fraud. U.S. District Attorney Sherri Lydon said 15 people were indicted. NCIS told the Washington Examiner five arrests were made and five people were served summonses on Wednesday. More than 250 additional individuals are being investigated and could be prosecuted.

The incident was investigated as part of an investigation called Operation Surprise Party, spearheaded by NCIS since January 2017. The Defense Criminal Investigative Service, Army Criminal Investigation Command, and Air Force Office of Special Investigations were also involved with the investigation, as were several outside civilian law enforcement partners.

"This enforcement operation sends a clear message about our unwavering commitment to protect our nation's service members so they can focus on their mission of winning wars and defending the American way of life. Working with our fellow federal agencies and state partners, we will continue efforts to stamp out sexual extortion impacting our communities," Andrews said.