Not enough is being done to protect children from injury under a "worrying" government plan to promote rugby in schools, public health experts have claimed.
Under a youth sport strategy announced after the London 2012 Olympics, the Government selected rugby union and rugby league among five sports to receive additional funding and support.
But academics at the Queen Mary University of London, writing in the British Medical Journal, said the UK's monitoring of injuries in children who played the sports was "inadequate".
Professor Allyson Pollock, along with two colleagues, wrote: "Given that children are more susceptible to injuries such as concussion and often take longer to recover fully, the Government's plan to increase funding of and participation in rugby in schools in the absence of a comprehensive system for injury surveillance and prevention ... is worrying.
"Only by collecting injury data and by providing feedback to individuals and organisations working on safety initiatives will the short and long-term effects of injury prevention programmes, whether for rugby or any other sport, be known."
The experts cited studies suggesting 12% of children and teenagers who play the game sustain an injury severe enough to be sidelined for seven days. Scrums were the "most dangerous phase of play", the researchers said.
They also highlighted the system of monitoring and prevention in New Zealand as a successful model.
But former England hooker Brian Moore, writing in the Telegraph, said the injury rate in rugby should be compared with other sports.
He said: "Without a ranking of risk per sport, parents have no way of knowing whether rugby is any more dangerous than any other sport and cannot make a reasoned choice.
"To try and prevent sport being promoted on the basis of such a flawed methodology is not only poor, it is wrong."