An eight-and-a-half hour stand-off took place at a high-security prison where inmates refused to get back into their cells, it has emerged.
It began at Evesham’s HMP Long Lartin at about 1700 GMT on Sunday.
The Ministry of Justice said a small number of prisoners was “involved in an incident of passive concerted indiscipline”. No-one was injured.
The incident will be investigated and the appropriate disciplinary action taken, a spokesman added.
The disturbance was resolved peacefully by staff at 0130 GMT on Monday.
The Ministry of Justice said it would look into the cause of the disorder as part of the investigation.