PRISONERS placed in an anti-extremism unit have complained that isolating them from the main population is an "injustice", a report has said.

Management of the separation centre at HMP Full Sutton has been "difficult" with "prolonged periods of disengagement" between inmates and staff, according to the Independent Monitoring Board (IMB) for the high-security jail near York.

In 2017, ministers unveiled plans to set up three specialist facilities as part of efforts to clamp down on radicalisation behind bars.

Moves to establish the "jails within jails" gathered pace after a review warned that Islamist extremism was a growing problem in prisons in England and Wales.

Before the separation centre at HMP Full Sutton opened in March last year, members of staff undertook training to enable them to better understand issues relating to radicalisation, "radical criminal culture" and Islam, the IMB's report noted.

It said the unit is in a small wing within the jail but functions separately from the rest of the prison. It was fully refurbished and has its own facilities including kitchen and education area.

The maximum number of inmates held in the centre last year was four, the board said. It has a capacity of eight.

The report said: "Prisoners have challenged the notion of being held in a separate unit, seeing it as an injustice.

"Men within the unit have perceived themselves to be discriminated against in a number of ways, and take the view that being held in the unit is discrimination in itself.

"This belief has resulted in prolonged periods of disengagement between prisoners and staff, and prisoners and an imam."

Men in the unit submitted 108 discriminatory incident report forms during the year, according to the report.

It added: "Management of the unit has therefore been difficult.

"Although facilities are good, the nature of the unit and the small number of prisoners held there means that relationships may become claustrophobic and it has been difficult consistently to engender good relationships between prisoners and staff."

Inmates can be moved to the specialist units if they are linked to terror plotting or considered to pose a risk to national security.

Those seeking to influence others to commit terrorist crimes, or whose extremist views are undermining good order and security behind bars, can also be taken out of the mainstream population.

The other prisons with separation centres, which were set up to tackle all forms of extremism, are HMP Frankland and HMP Woodhill.

A Prison Service spokeswoman said: "Separation centres are designed to house only the most dangerous terrorists and extremists - we do not have targets to hit and do not simply fill them arbitrarily.

"Instead we work closely with police and other agencies to very carefully assess which prisoners should be housed in these centres to make absolutely sure that we manage this threat appropriately."

Overall, the monitoring board said HMP Full Sutton remains a safe environment for prisoners and staff.

Sally Hobbs, chairwoman of the IMB, said: "HMP Full Sutton houses some of the country's most serious offenders. Our overall assessment is that they are treated fairly by the regime there."

Care is taken to make family visits "welcoming and comfortable", according to the report.

It said: "Prisoners and their family and friends may eat a meal together, officers take photographs which the men can purchase for a small sum and activities are provided for those who would like to take part."