Levels of violence among child criminals are "too high" and need to be tackled as a priority, according to a report.
Inspectors raised concerns about the conditions at Cookham Wood Young Offender Institution in Kent, which holds up to 188 boys aged between 15 and 18. It was branded "not sufficiently good" in all areas of an inspection in September after a deterioration in quality of care since 2018.
Most of the inmates are aged 17 and almost half (45.6% or 78 offenders) are serving time for a primary offence of violence against the person.
The problems were raised as the site was running at "near capacity" with offenders transferred from Feltham A YOI in the wake of there being an "extraordinary" plunge in safety levels at the west London institution, prompting inspectors to call on Justice Secretary Robert Buckland to intervene and tackle the concerns raised.
Use of force by staff had increased and was high, according to the report. Just over a quarter of children (28%) were locked in their cell during the school day with access to the gym and library restricted.
Most had just five hours a day during the week and two hours at weekends outside their cells, inspectors added.