Inmates have taken over a wing at a Category A jail tonight.
Staff were allegedly attacked with pool balls at HMP Long Lartin, near Evesham, Worcestershire.
Around 10 inmates caused the disturbance in which they damaged the wing, BBC understands.
HMP Long Lartin is home to 622 lags, including some of Britain's most notorious.
A Ministry of Justice spokeswoman said: "Specialist staff have been deployed to manage an ongoing incident at HMP Long Lartin.
"We are absolutely clear that prisoners who behave in this way will be punished and face extra time behind bars."
The injured officer is said to have taken themselves to hospital after sustaining a minor wound.
A report from HM Chief Inspector of Prisons last year said 500 of the inmates there are some of the country's most "dangerous and serious offenders".
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Nathan Matthews, who killed 16-year-old stepsister Becky Watts, was sentenced to life at the prison in 2016.
And Christopher Halliwell is jailed here after murdering Sian O'Callaghan, 22, and Becky Godden-Edwards, 28, in Wiltshire.
Jake Fahri is serving life at the prison for the murder of Jimmy Mizen, 16, in Lee, southeast London.
The killer pierced the boy's neck with a large shard of glass in a bakery.
There is no indication these lags were involved in tonight's disorder.
Ian Watkins, of former rock band Lostprophets, spent time there after he was jailed for 13 sexual offence charges, including attempted rape of a baby.
The 42-year-old since been moved to HMP Rye Hill in Warwickshire.
Last September, six officers were hurt in disorder at the jail.
Two of whom had suspected broken jaws.
Seven prisoners were put into isolation after the anarchy.
