Thousands of children are needlessly being locked up in young offenders institutions, a think-tank warned on Sunday.
The Centre for Social Justice said many detention centres were being used to care for children, adding the youth justice system needed to be radically overhauled.
According to the think-tank's report, there are some 5,000 children detained, with each place costing between £69,600 and £193,000. Three out of four child criminals commit further offences within a year of being released.
The report claims young offenders institutions should not be forced to step in when council-run social services have failed to help a youngster, adding that in one case a child was held after he threw a bowl of Sugar Puffs over a care worker.
Instead, under-18s should only be imprisoned for the most serious crimes, with parents and teachers taking a "common sense" approach and dealing with misdemeanours.
In the preface to the report, Gavin Poole, executive director of the CSJ, wrote: "Reform of the youth justice system needs to go further and deeper.
"This review by no means seeks to excuse the behaviour of these young people. We strongly believe in young people taking responsibility for their actions and being appropriately penalised; no offender should ever be allowed to think they are immune from the law.
"However, if society wants to see youth crime tackled it must be prepared to make greater efforts to understand and address its drivers.
"As a society, we can do better than simply condemn these children for their crimes. We believe there are more effective and demanding ways of delivering justice than through punishment alone.
"Many young people fall into the system unnecessarily and do not receive the help they need to free themselves from it.
"Custody is sometimes neither a protective nor a productive place for children, and community orders can be equally ineffective.
"Moreover, despite years of good intentions, many young people leaving custody are still not being provided with the basic support they need for rehabilitation.
"Many of these young people consequently become the life-long persistent offenders who are saturating our adult prisons."
A Ministry of Justice spokesman said: "We accept that low level youth offending is not always best dealt with by prosecution - which is why a range of techniques are used to tackle younger offenders, including out-of-court disposals, robust support and interventions.
"Key reforms taking place include young people paying back to victims, financial support to turn around the lives of 12,000 troubled families, and new programmes designed to tackle the root causes of reoffending."