The government is to consider allowing staff at young offenders institutions in England and Wales to use batons to control children as young as 15.
There were 18,000 assaults in YOIs between 2003-2006
Staff are currently allowed to use them only against those aged 18 and over, but that policy is to be reviewed.
The Prison Officers Association says its members need more protection from a rising number of assaults and to help bring situations quickly under control.
But critics fear the move could be counter-productive and fuel violence.
Glyn Travis, assistant general secretary of the Prison Officers Association (POA), told BBC Radio Five Live that officers often got hurt.
"The injuries vary from broken noses, compressed fractures of cheekbones, fractured eye sockets, ears being bitten off, pens being shoved through people's faces, slashes," Mr Travis said.
"There is a serious violent problem within the criminal justice system and we believe it's out of control."
Colin Moses, national chairman of the POA, added that the deterrent was needed to defend officers and those in their charge.
The POA said some of his members had suffered long-term psychological problems after being assaulted by children.
But Martin Narey, chief executive of children's charity Barnardo's and former chief executive of the Prison Service, said the use of batons to control children was not necessary, and that its use would "promote a sense of deep mistrust and suspicion".
"Not for the first time, the POA underestimate the success of their own members in defusing unrest without the use of force," he said.
He added that custody should be an opportunity to redeem the child.
"You do that by treating child prisoners firmly but with dignity, by educating them and making them employable, not beating them with truncheons," he said.
Recent figures, compiled by the Howard League for Penal Reform, show there were more than 18,000 assaults in young offenders institutions (YOIs) between 2003 and 2006 - 2,500 of which were attacks on staff.
Frances Crook, director of the league, said a recent parliamentary answer had revealed that nine out of the 10 most violent places of detention in the UK were YOIs, where the majority of those held are aged between 18 and 21.
"The National Offender Management Service estimates that 11% of prisoners involved in serious assaults are children, despite being only 3% of the population," she said.
Ms Crook said batons were "always the wrong answer" and would make YOIs even more violent for staff and inmates.
"There are huge numbers of young men in prison with very serious mental health problems and threatening them with batons is completely inappropriate."
Ms Crook said prisons had created their own problems by keeping young people cooped up indoors without exercise.
At the start of October, the league says 3,006 children were in custody in England and Wales. Of these, 2,512 were in YOIs.
A Prison Service spokesman said: "It has been prison policy for a number of years that batons are not routinely used in the juvenile estates."
But the government said it would start a review in the autumn of the ban on baton use to control younger children, although there was no timetable for a final decision.