A teenager has died after suffering a "serious head injury" while playing a rugby-style tackling game popular on social media, police have confirmed. The 19-year-old from New Zealand - identified in local media as Ryan Satterthwaite - passed away in hospital on Monday, having played a game of 'run it straight' with friends in the city of Palmerston North the day before. The game sees two players, one with a ball and the other the tackler, charge at each other with no protective gear in order to recreate the high-impact collisions seen in rugby and knock each other down. While it has been played casually in Australia and New Zealand for years, 'run it straight' has recently become a viral challenge online, with videos of people running at full speed into one another clocking up tens of millions of views on platforms like TikTok and Instagram. In a statement, Manawatu Area Commander Inspector and police spokesperson Ross Grantham said: “This young man’s death is an absolute tragedy and my thoughts are with his family and friends. “The tackle game … was based on a social media-driven trend, where participants compete in full-contact collisions without protective gear. "While this was an impromptu game among friends, not a planned event, this tragic outcome does highlight the inherent safety concerns with such an activity," Inspector Grantham added. "We would urge anyone thinking about taking part in a game or event like this to consider the significant safety and injury risk." Despite critics warning that it could lead to head trauma and brain injury, the game has not just taken off online but has also been endorsed by some professional rugby players and has led to tournaments being held. Last week, one such event - Runit Championship League - was held in Auckland, having being first held in Australia in March, with a prize of around $20,000 up for grabs. The event saw two men retire from the competition due to head injuries, with videos showing one of them appearing to have a seizure following a collision, according to Radio New Zealand . Tournament organisers RUNIT promotes the game as "the world's fiercest new collision sport" with "strength and grit" being rewarded. A Runit Championship League final had been planned to be held in Auckland with a reported $200,000 prize on the line, but the Trust Arena - where the 'trials' had already taken place' now says it will not host the event. “The initial Runit trials were held at the Trusts Arena, but a contract had not been signed in relation to hosting the final event,” said the stadium's general manager of community engagement Lynette Adams. “Following the trials, it was clear from commentary that there was overwhelming concern for the high-risk nature of the event. Safety of all participants at our venue is paramount and this activity presented safety considerations that we could not overlook. “We therefore made the decision not to allow any further Runit events at our venue and the event promoter was advised accordingly last week." In a statement issued to the Guardian , RUNIT said the 19-year-old's death was tragic and said it did "not encourage any copying of the sport", adding that its events involve participant screening, medical assessments and strict guidelines on how and where to tackle. “Any contact sport like boxing, martial arts or combat-style activities should only be held in highly controlled environments, which include professional medical supervision and support,” it said. “We do not encourage any copying of the sport as it should only be done under the strict conditions.”