Muslim extremists who "present a particular and enduring risk to national security" in prison are to be contained in special units and put through "deradicalisation" programmes.
A Government review into Islamist extremism in Britain's prisons recommends that a subersive "subset" of extremists in the nation's prisons is removed from the general prison population and held separately. Currently, they are dispersed widely through the general prison population.
Justice secretary Liz Truss also announced that extremist books are to be stripped from prison libraries and prison chaplains are to be vetted more effectively.
The report also recommends an independent advisor on counter-terrorism in prisons be appointed and that all incidents of extremism and violent threats to prison staff are recorded, along with tougher penalties for those responsible.
Prison staff are to be trained in how to tell the difference between religious and cultural traditions. There is to be greater focus on the "safe management" of Friday prayers, with sanctions for abuse or misuse of all acts of worship.
The review was led by Ian Acheson, a Home Office official who was previously a prison governor.
The full report, finished in March, remains classified because of the contents, but the summary published today shows clearly the severity of the threat presented by Islamist extremism in prisons.
"Islamist ideology can present itself in prisons as a struggle for power and dominance in which perceived weaknesses are exploited by a gang culture which threatens or undermines legitimate authority and security," the report says.
Acheson found evidence of a "growing problem" within prisons.
Some prisoners "aspire to acts of extreme violence", the report says.
In addition, both Muslim and non-Muslim prisoners serving sentences for crimes unrelated to terrorism are nevertheless "vulnerable to radicalisation by Islamist Extremists", it says, warning that the number of prisoners guilty of offences relating to terrorism and extremism is likely to increase.
The report cites the reported figures of at least 800 Britons who have travelled to Syria and Iraq to fight, while others have travelled to Afghanistan, Somalia and Yemen.
"A significant number of these have returned to the UK, of whom a portion will enter the criminal justice system." This will have "knock-on consequences" for radicalisation in prisons.
Among the tactics used by the extremists are "aggressive" attempts to persuade others to convert to Islam, attempts to prevent staff searches by claiming dress is religious, extremist books in chaplaincy libraries and exploitation of staff fearful of being labelled racist
There are currently around 69 full time, 65 part-time and 110 other Muslim prison chaplains. About two-thirds are from the conservative Deobandi grouping.
