Inmate arrested after fire at Dorset prison
A 29-year-old prisoner has been arrested following a fire on the roof at HMP Guys Marsh in Dorset.
Following an initial investigation, he was arrested on suspicion of arson with intent to endanger life and is being questioned.
The blaze was reported to have been started by an inmate at the prison who stripped off and torched his clothes.
Sixty four prisoners were evacuated while firefighters tackled the blaze overnight, having been called to the scene around 8pm on Friday.
There were 21 fire engines at the scene at the height of the incident.
During the prison's last inspection, investigators found it was in "crisis" and managers 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.
The Category C facility holds prisoners serving life sentences as well as those undergoing drug addiction treatment, according to the Ministry of Justice website.