Inmate admits arson after Guys Marsh prison fire
An inmate has admitted starting a large fire which led to the evacuation of part of a prison.
The blaze, at HMP Guys Marsh in March, began when Nigel Saunders, 29, reportedly climbed on to a roof and set fire to clothing.
A total of 64 prisoners in a housing block had to be taken to a secure area.
Saunders, who pleaded guilty at Bournemouth Crown Court to arson with intent to endanger life, will be sentenced on 4 August.
It took 21 fire engines to control the blaze, which caused substantial damage to the jail near Shaftesbury.
BBC home affairs correspondent Danny Shaw previously reported the prisoner was drunk and protesting at changes to the prison regime.
A source said the protest started at about 17:00 GMT on 10 March and hours later the prisoner started ripping off roof tiles before setting his clothes alight.
In April, an Inspectorate of Prisons report said the jail "remained unsafe", with high levels of drug use and assaults on staff.
The inspection, carried out in December, highlighted prisoners "self-isolating" for weeks or months for their own protection.
Guys Marsh is a category C training and resettlement jail which holds around 550 adult male prisoners.