The Mercer County Prosecutor’s Office says it has arrested 21 men in an undercover online sting targeting child predators.

Operation Risky Business was a multiagency investigation to target predators who used social media to attempt to lure underage boys and girls for sexual activity.

Undercover police officers posed as the children and got the men to agree to meet them for sex at the Hamilton Train Station and at a residence in town.

The men were all charged with attempted sexual assault. Four of the suspects were already on the registered sex offenders list.

Officials say that one man was charged in two cases because he was chatting with two separate undercover officers.