Muslim prison gangs are trying to force other inmates to sign up to Islamic radicalism, prison officers have warned.

Extremists at high security HMP Whitemoor in Cambridgeshire are said to be pushing a "strict and extreme" interpretation of Islamic practice.

Chief Inspector of Prisons Anne Owers said: "There was a perception among officers that some Muslim prisoners operated as a gang and put pressures on non-Muslim prisoners to convert, and on other Muslim prisoners to conform to a strict and extreme interpretation of Islamic practice.

She found staff were reluctant to tackle "inappropriate behaviour" and was told Muslim prisoners were able to "police themselves".

She was told: "The new gang are the Muslims. The Muslim group is a big group and others are looking for protection.

"Those who are isolated are looking for protection and so are the ones converting as they won't get help from screws."

Phil Wheatley, Director General of the National Offender Management Service, said: "The Chief Inspector is right to highlight the challenges and risks Whitemoor is facing. It is also important to recognise the action being taken to manage challenging prisoner profiles.

"A more sophisticated approach to addressing bullying and the management of bullies and their victims is now in place and is bringing improvements.

"Work to improve the relationships between staff and prisoners is a priority and measures have been implemented to tackle this, including training to develop staff understanding of the growing Muslim population."