An Eastbourne police officer has shared guidance for parents after a sinister online challenge has resurfaced.
The 'Momo challenge' features a scary-looking doll face which sends the viewer violent images and instructs them to partake in dangerous challenges, such as waking up at certain hours.
It has also been linked to self-harm.
The challenge has resurfaced after allegedly being inserted into videos on YouTube Kids, sparking concern among parents and teachers across the country.
PC Rachel Bourne, a prevention youth officer based in Eastbourne, tweeted guidance from National Online Safety about what parents should do if their children are worried or have been affected by the online phenomenon.
She said: "Lots of concerned schools/parents/carers are worried about the #MomoChallenge which has resurfaced online - please take a look at this useful guide from @natonlinesafety which has great information and helpful tips to keep #YoungPeople safe."
While YouTube monitors its content, videos with 'Momo' can be viewed thousands of times before being taken down.
The top tips from parents are to flag or report any content online they think is suspicious, and to sit their children down and talk to them about the phenomenon, and explain that it is not real.
According to the guidance, the 'Momo' face is from a sculpture that featured in an art gallery in Tokyo and has been appropriated for the online challenge.