The drinking game Neknominate is taking the UK by storm, as participants attempt to drink dangerous quantities of alcohol to "beat" other contestants.
Neknominate is a phenomenon in which young people are nominated to drink excessive amounts of alcohol, while taking part in dangerous and potentially fatal activities. Once they have completed their "neknomination" in a video, they nominate someone else to do the same.
Some have even attempted to drink toxic, non-alcoholic substances to "show off" to friends and beat their opponents.
In this video, a man can be seen pouring WD40 lubricant into a glass, before downing the liquid.
Participants have posted videos of eating raw chicken skulls, drinking urine and even dangling from helicopters while drinking excessive amounts of alcohol, urged to carry out the tasks by peer pressure.
In Ireland, police are investigating the deaths of two young adults as a result of the drinking game. The body of Jonny Byrne, aged 19, was recovered from the River Barrow in County Carlow. He had been seen entering the water near Milford Bridge on Saturday evening after taking part in the game.
Officials in Dublin are also investigating the death of a 22-year-old, whose body was found in a house in nearby Macken Street early on Saturday morning. A Garda spokesman said the death of Ross Cummins was not suspicious, yet media reports claimed his death was linked to the Neknominate phenomenon. The cause of death is yet unknown.
Clips posted on social media sites by players include a man drinking a beer, nailing his testicles to a table, then drinking another beer.
In another video, a skateboarder chugs beer through a pipe - while riding down a steep hill on a main road into oncoming traffic.
One participant posted a video of a man completing his neknomination by drinking beer out of a toilet, while his friends hold him up by his feet.
Another trend concerning authorities is "skidnominate", a dangerous escalation of the drinking game where participants film themselves doing burnouts, skids and other stunts in their cars.
Following the deaths in Ireland, Frances Fitzgerald, the Minister for Children and Youth Affairs said: "Above all, it represents further evidence that we still have a long way to go in denormalising binge-drinking among Irish youth.
"Young people take their cues from our broader society's general attitude to drinking, and the popularity of Neknominations shows we still have a long way to go in developing a healthy societal attitude to the consumption of alcohol."
Prof Michael Farrell, the director of the University of NSW's National Drug and Alcohol Research Centre, condemned the game. He told the SMH: "It's like Jackass and that type of wild behaviour and it's not necessarily very impressive."
He added: "The main issue is the question of scale and context. In general it looks like it could get people into a lot of trouble, with a lot of pressure to drink. It's competitive, heavy drinking, and that tends to end up with people coming to serious grief through alcohol poisoning. It isn't a thing to be encouraged at all."