A riot at a prison on the Isle of Sheppey in Kent saw about 60 inmates take control of an entire wing, prompting fears of copycat disturbances in other jails across the country.
Video footage of the unrest saw prisoners go on a rampage at HMP Swaleside on Thursday evening (22 December), with one heard shouting "Swaleside is burning" as others ran through the jail wing with no guards in sight.
A photo taken by an inmate shows another brandishing a plank of wood while surveying a scene of destruction, while there were reports other prisoners lit fires.
Specialist Tornado squads of riot-trained guards had to be drafted in to help quell the six-hour unrest.
The prison service said there were no reported injuries from staff or inmates, while police said they had launched an investigation.
The disorder at the category B training prison, which began shortly before 7pm, is the fifth to take place in the country's jails over eight weeks.
HMP Birmingham last week saw one of the worst riots in decades as hundreds of prisoners took over four wings during a 12-hour rampage, causing up to £2m (€2.35m $2.46m) in damage.
Serious damage was also caused at Lewes prison in East Sussex at the end of October during six hours of unrest, followed by disorder at HMP Moorlands in South Yorkshire and HMP Bedford.
The disorder at HMP Swaleside, which houses about 1,100 inmates, has piled yet more pressure on Justice Secretary Liz Truss and the Ministry of Justice, who will be fearing copycat disturbances erupting across the overcrowded and under-staffed prison service.
The Prison Officers Association chairman, Mike Rolfe, said cuts to staff numbers had led to a breakdown in the relationship with inmates.
"What you have is a really unhelpful mix around the prison estate of prisoner-staff relationships now, where staff numbers have been cut so that staff don't feel confident or empowered to be able to do their role. That's led to a breakdown of the relationship," he told BBC Radio 4's Today programme.
"What you need to foster a good environment is prison officers who are able to work with prisoners but then help mentor them towards education and work, because most prisoners don't want to do that instantly, so you need to have healthy relationships to start turning their lives around. We have completely lost that at the moment, there's a real breakdown and division between the two groups."
An HM Inspectorate of Prisons (HMIP) report in July warned levels of violence at Swaleside prison were far too high, with many of the incidents serious. A survey found 69% of inmates had felt unsafe at some point – significantly higher than at similar facilities.
The shadow justice spokesman, Richard Burgon, said: "This is yet more troubling news from our prisons. In July, the independent monitoring board said this prison is not safe and staff shortage is the major cause. As with the Birmingham prison, the public will once again wonder what action the justice secretary actually took in response to the board's concerns. She needs to tell us."
Last month, the justice secretary announced the "most far-reaching reform of our prison system for a generation".
A Prison Service spokeswoman said: "The challenges in our prisons are longstanding and won't be solved overnight but the justice secretary is committed to making sure our prisons are stable while we deliver wholesale reforms to the prison estate to help offenders turn their lives around and reduce reoffending."