Video report by UTV reporter Marc Mallett
Teachers in Northern Ireland are signing off sick in 'real distress' after being targeted by TikTok posts rating their performance and making serious allegations.
Police are investigating the 'rate my teacher' trend following a series of complaints from schools - and are warning pupils that their posts could be considered criminal offences.
Officers say some TikToks are taking the form of fake accounts are being set up in real schools' names.
Some videos on the popular social media platform have featured photos of school staff, along with 'inappropriate' comments, officials said.
A PSNI spokesperson said officers had received complaints about posts containing potentially criminally offensive content.
NASUWT Northern Ireland national official Justin McCamphill told UTV the union had received complaints from 10 schools so far.
He said: "Some seem to be a series of pictures with damaging comments about teachers.
"Members were getting in contact with us who were in real distress about it, and it really took off after Halloween."
Schools had been unable to tell who was posting the material in some cases, Mr McCamphill added.
He warned: "There are teachers who have signed off sick because of the things that are being said."
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Mr McCamphill said some union members had complained about posts containing serious allegations about teachers that appeared "defamatory."
A PSNI spokesperson said: "Over the last few weeks, we have had a number of incidents where fake TikTok accounts for local schools have been set up.
"These accounts have then posted images of school staff with inappropriate comments."While those involved may not see the harm in their actions, they are causing real distress to the individuals targeted.
"Some of this content is abusive and could potentially constitute a crime under Misuse of Telecommunications or Harassment."
A spokesperson for the Education Authority said: “We are aware of this growing online trend which is completely unacceptable. We will continue to monitor the situation and provide relevant support and guidance as appropriate.”
Concerns about the TikTok trend come as the Education Department launched its new Safer Schools app this week, in a bid to boost online safety for youngsters.
UTV has attempted to reach TikTok for comment.
A spokeswoman for TikTok told the BBC: "Our community guidelines make clear that we do not allow accounts that impersonate people in a deceptive manner, nor do we tolerate content that contains bullying or harassment, statements targeting an individual, or hateful speech or behaviour.
"We remove any content that violates these guidelines."
Anyone aware of incidents of this nature or with information to share is being urged to contact PSNI on 101.