A prison wing is understood to be under control after specially-trained prison security teams were drafted in to deal with an “ongoing incident”.
So-called Tornado squads, equipped to deal with riots, were sent to HMP Hewell near Redditch, Worcestershire, after trouble broke out on one of the prison’s wings on Saturday.
It is understood a handful of prisoners at the category B jail were refusing to follow prison officers’ orders and had been attempting to cause damage to the wing.
Men shouting and swearing, as well as dogs barking, could be clearly heard coming from the scene late on Saturday.
Several loud quickfire bangs, thought to be distraction bursts being used by the prison authorities, were heard at the scene, greeted by loud shouts thought to be coming from inside the affected wing.
It is understood the incident ended shortly after the bangs were heard at around midnight, and prison authorities are now back in full control of the affected wing.
From about 7.30pm, unmarked vans using blue lights and sirens started arriving at the site which is run by HM Prison Service.
A steady stream of vans and minibuses was seen arriving at the jail’s front entrance, carrying and unloading Tornado squads carrying backpacks full of equipment.
Hewell jail, which opened in its current form in 2008, is made up of six housing blocks or wings – while there is a separate open prison called the Grange.
The main site, which houses about 1,000 inmates – some of whom are category A remand prisoners – is surrounded by farmland.
In an announced inspection report published in January, Hewell was described as “a prison with many challenges and areas of serious concern”.
Peter Clarke, chief inspector of prisons, said the “main concerns at the closed site were regarding issues of safety and respect”.
He said levels of violence were “far too high”, communal areas “dirty” and many cells over-crowded, with some described as “filthy”.
Almost two thirds (60%) had told the inspection team it was “easy” to get hold of drugs inside.
Inspectors also found levels of self-harm had increased, a quarter of prisoners “felt unsafe”.
A Prison Service spokesman said: “We are currently managing an ongoing incident on a wing at HMP Hewell.
“A small number of prisoners are involved and there is no risk to the public.”
The spokesman added: “We are absolutely clear that offenders who behave in this way will be punished and face spending extra time behind bars.”