A prison guard needed hospital treatment after being injured in a riot.
About a dozen inmates were involved in the incident at Rochester Young Offenders’ Institution on Saturday.
The trouble broke out in the exercise yard at about 3pm, but details have just been released.
A member of staff was knocked to the ground as the guards attempted to bring the situation under control.
The employee, thought to be a woman, had to be taken to hospital suffering from concussion.
A Prison Service spokesman said: “Staff intervened quickly and six prisoners were taken to the segregation unit.%