A prison roof has been set alight after an inmate allegedly stripped off and torched his clothes.

Firefighters were tackling the fire in the early hours of Saturday after a prisoner scaled the roof at HMP Guys Marsh in Dorset.

It is believed the inmate was wearing a "couple of sets of clothes" when he clambered up to the roof during disruption at the Category C prison on Friday evening.

Around 60 inmates were taken to a secure area in the prison while the fire was tackled and the scale of the damage ascertained.

A Prison Service spokesman said: "Staff are responding to an ongoing incident involving one prisoner at HMP Guys Marsh.

"There is no danger to the public and staff are working to bring the incident to a safe conclusion as quickly as possible."

The inmate was protesting against changes to the prison regime and is believed to have been drunk at the time, according to the BBC.

During the prison's last inspection, investigators found it was in "crisis" and staff had "all but lost control".

The unannounced inspection, triggered by "concerning intelligence", found gangs "operated openly" in the facility, which was overcrowded with 543 male inmates in November 2014.

Violence, largely driven by the drug "Spice" and illicitly brewed alcohol, was "very high" and inmates lived in fear, the HM Inspectorate of Prisons wrote in the 2015 report.

In November, images of inmates eating steaks and takeaways captured on smuggled mobile phones at the prison were condemned as "totally unacceptable" by Downing Street.

Dorset Police said officers discovered the "large fire" after being called at 8pm on Friday.

The prisoner, who police believe deliberately started the blaze, was being treated by paramedics as a precautionary measure and was not immediately arrested.

Superintendent Caroline Naughton said: "This was an isolated incident. An investigation is now under way to establish the exact cause of the fire.

These enquiries remain ongoing.