Parents and guardians have been urged to speak to their children after inappropriate texts messages were sent to post-primary school pupils from a number outside Ireland or the UK.
Police say an investigation is ongoing and have urged those with responsibility for children to engage with them.
A spokeswoman for the PSNI said: “We would encourage parents to have regular and open conversations with their children about who they are speaking to on their phones and their wider online activities.
“Having an understanding of the features of their mobile devices, apps and games your children are using, particularly when there is the ability to connect with people they may not know, is important for keeping them safe.”
The spokeswoman said police work with other agencies and appealed to parents who are concerned that their children are being groomed, or at risk, to contact them.
