An anonymous chat app linked to cyber bullying has been suspended in the Republic of Ireland, but children in Northern Ireland can still download it.
SimSimi temporarily removed access in the Republic this week, with a message: “I do not talk in Ireland for a while”.
But schools in Northern Ireland are alerting parents about the app and asking them to check children’s phones.
And police in County Down have sent out an alert warning that messages can be both “abusive” and “explicit”.
The app allows users to type in people’s names.
They then get an anonymous, sometimes insulting and nasty message back.
St Paul’s High School, Bessbrook, sent out a warning about the “potential dangers” linked to the app – the school said it had been tipped off by some responsible pupils.
It has asked parents to remove the app from their children’s phones.
Principal Jarlath Burns said: “The school is concerned that the app is still available and is active in Northern Ireland, and would encourage the makers of the app to adopt the approach they have implemented in other parts of the island.”
Mr Burns said the school has used its social media networks to warn parents and ask them to monitor their children’s online behaviour.
“This critical pastoral message has been reinforced at school assemblies all week, and form teachers and pastoral leaders are continuing to deliver this advice in class time,” he said.
Assumption Grammar School, Ballynahinch, also sent out a tweet urging pupils to remove the app from all devices for their own safety.
On its Facebook page, PSNI Down said it was unusual for police to highlight apps, but the SimSimi app gave them “cause for concern”.
“It appears to be a computer generated chat room where you talk to a very abusive computer!
“We had only been using the app for two minutes before we got quite the surprise!” says the post.
“Please be aware of it and its explicit nature! The app is rated as 17+ but I am twice that age and was really shocked at some of the stuff that came back!
“We have reported it to the App Store and will include it in our Internet Safety talks but parents, carers and internet users should keep an eye out for it and avoid.”
The app stems from South Korea.
It works by using both artificial intelligence and user-generated content – scanning conversations in its database and giving a response based on that. It was originally marketed as a “fun playful robot”.
James O’Higgins-Norman, director of the National Anti-Bullying Research Centre at Dublin City University, said it was being downloaded “in huge numbers” across Ireland last week.
“We saw the potential for cyber bullying and we began to put out warnings through the media to parents and to schools,” he told the BBC’s Good Morning Ulster on Friday.
Catherine Flanagan, a secondary school teacher in Dublin, said the app “took of” within a matter of a few days. She was alerted by a student who was worried about her 11-year-old sister.
“In primary school, students were getting messages when they put in their name and they couldn’t understand where that had come from,” she said.
“Some of the responses were very nasty. What started as a bit of fun had quite quickly become something where students were being insulted about being too fat or too ugly and very personal things, things they might only know about each other.
“It became something much more sinister and harder to deal with.”
Her son, Jake, 15, said the app quickly became “a massive hit” in school.
“Almost everyone had it and, at the start, it was a bit of fun,” he said.
“But then people were putting in mean comments about people, and there was no way of telling who had said it. For one friend, at the beginning it was all fine and inside jokes, but within a couple of days every time he looked up his name, something mean was being said. It hurt him a lot and he became very down.”
The BBC asked the app developers in south Korea for a statement, but so far has had no reply.