The latest online craze to spread on Facebook - daring users to post video clips of a 'cold water challenge' - has claimed the life of a father in Germany.
Eleven members of a bowling club in Isselburg, on the Dutch border, had filled a mechanical digger's shovel with 2,000 litres of water, which was to be poured over them.
But as the shovel was lifted into the air, the digger tipped over and the shovel hit the group - killing one man and injuring five of his friends.
Four of the injured were taken to hospital following the accident.
The craze is relatively new to the UK and Ireland, where typical videos show users having a bucket of cold water tipped over their heads and nominating others to do the same.
A PSNI spokeswoman told the Belfast Telegraph that while there were water challenges in Northern Ireland - used to raise money for charity - it was not aware of "extreme challenges circulating here".
"We are aware of the online water challenges raising money for various charities," it said
"In other countries some of the challenges have been extreme and have involved people putting their lives at risk jumping into large bodies of water.
"We are not aware of any such extreme challenges circulating here.
"We would simply encourage people to be sensible and be safe."
'Cold water challenge' follows viral drinking game 'Neknominate', which saw thousands of Northern Irish people share videos of themselves downing a drink.
The online phenomenon was blamed for the deaths of two young men in the Republic of Ireland when 22-year-old Ross Cummins and 19-year-old Jonny Byrne were found dead in separate incidents at the start of February.
In the US, several people have been injured participating in cold water challenges, which typically involve dares such as jumping into cold water.
French police have warned youths about its dangers - which in France is called 'A l'eau ou au resto' (into the water or to the restaurant) - after it left one person dead and another severely injured.
A 19-year-old drowned when he rode his bicycle into a port in Beganne in western Brittany while a friend filmed him.
Another youth was permanently injured after diving headfirst into shallow water near Calais.
Charities in New Zealand, meanwhile, have reportedly raised thousands of dollars through challenge donations and forfeits.