A group of South Carolina inmates allegedly used smartphones to pose as underage girls in order to trick U.S. service members into paying them thousands of dollars, according to an investigation by the Naval Criminal Investigative Service.

On Wednesday, agents from military criminal investigative organizations served arrest warrants and summonses to those accused of participating in the "sextortion" ring. The investigation into the catfishing scheme was titled "Operation Surprise Party."

NCIS estimated that 442 service members from the Army, Navy, Air Force and Marine Corps were scammed out of a combined $560,000.

"With nothing more than smartphones and a few keystrokes, South Carolina inmates along with outside accomplices victimized hundreds of people," said Daniel Andrews, director of computer crime investigations for the U.S. Army Criminal Investigation Command.

Officials said the inmates were assisted by associates on the outside in targeting military service members on social media and dating websites.

The inmates pretended to be women, engaging in romantic relationships with the men, and exchanging pictures with them, according to officials.

Then, they would pose as a police officer or older family member, claiming the person they had exchanged pictures with was a minor. The inmates would extort money from the military members, who believed they now possessed child pornography, in exchange for not pursuing charges.

"This despicable targeting of our brave service members will never be tolerated," Naval Criminal Investigative Service Director Andrew Traver said in a statement. "We will not allow criminal networks to degrade the readiness of our military force."

Approximately 250 people are still being investigated for their possible roles in the scheme.