Worried school parents in Dubai have been sharing advisories with each other via social media regarding an online craze, which has reportedly been linked to hundreds of teen deaths in Russia, reported Khaleej Times.

The chilling challenge, called Blue Whale, is a 'suicide game' allegedly run by an online social media group in which gamers are being urged to complete a set of daring challenges over a 50-day period, before then being told to kill themselves.

In a Whatsapp message to Khaleej Times, the advisory read: "Any parents out there or anyone that knows of any kids playing an online game called 'Blue Whale', please get your kids off this game. It sets them 50 challenges and the last one is to commit suicide."

And when the message was shared with parents here, many said it was "terrifying and frightening".

"There are some sick people in the world," one British mother said, with another adding that the news has been shared to parents back in her home country of the UK.

"Schools are being warned there because there have  been cases documented in the UK. This is very real, terrifying and so sad to think that this is happening across the world with our vulnerable children."

Allegedly originating in Russia - where more than 100 suicide cases have been linked to the game - another concerned Dubai parent said it's been sickening reading the news about Blue Whale.

"(These teens) are seriously self-harming in countries as far and wide as Brazil, Portugal, and Russia, just to name a few."

Although there have been no related reports of the game reaching the UAE as yet - or if it even exists - one parent told Khaleej Times that her daughters' school sent out a warning letter to parents on Monday, urging them to exercise extra caution when it comes to what their children are downloading.

And after reading the Whatsapp advisory, Dubai-based British mother T.R. wrote on Facebook: "We need to keep an eye on what our kids are watching. I've spoken to (my daughter) about it but the only thing we can do is tell them that this is certainly not a normal way of life. A scary world we live in now."

How the game works 

According to online reports, Blue Whale initially sets challenges ranging from watching psychadellic horror movies to cutting shapes into their skin, with the final challenge being suicide.

To complete each challenge, users are urged to send photographic evidence back to the game creators as proof, or they will send threats.

It is thought the creators of the application-based game prey on vulnerable teens online before asking them to download the app and take the challenge. Once downloaded the user's phone is then hacked and the game cannot be deleted, meaning they can access all your details.

A case of De ja vu

In 2015, authorities here cautioned parents, teachers and schools against a game promising contact with spirits and demons. Called the 'Charlie Charlie Challenge', the game went viral over the Internet, reaching school students in the UAE too.

The game required two pens placed on top of each other creating a grid with the four sectors labelled yes and no. The players then posed a question to the 'supernatural being' named Charlie by saying "Charlie, Charlie, come play with me".

As a result, police organised awareness lectures in schools and told students that the game was just a cinema trick and to avoid playing it with friends.