A culture had been established whereby there was an obligation on children to fight with children from a different postcode, gang or wing, inspector found.
HMP & YOI Chelmsford was found by inspectors to be a violent and unsafe prison, with large volumes of drugs smuggled in by the many organised crime gang members in the Essex jail.
HMYOI Brinsford must address a "dreadful" rise in self-harm by young adult prisoners and change a regime in which they are locked in cells for long periods of the day, according to prison inspectors.
Inspectors found Cookham Wood young offender institution, holding 161 boys, to be less safe and more violent than at the previous inspection in 2016, with little evidence of an effective strategy to reduce violence.
Prison reform will not succeed unless the violence and prevalence of drugs in jail are addressed and prisoners are unlocked for more of the working day, said Peter Clarke, Chief Inspector of Prisons. Today he published his second annual report, for 2016-17.