Young offenders 'are being forced to convert to Islam'

They also criticised the health care of mentally ill young people at Feltham young offenders' institution in west London, where a white inmate with a personality disorder killed an Asian teenager with whom he was sharing a cell. Zahid Mubarek, 19, was beaten to death by Robert Stewart, who was known to be racist psychopath, five years ago.

Although Anne Owers, the Chief Inspector of Prisons, said race relations were improving at the centre, she raised serious concerns about the level of intimidation faced by inmates. She said "bullying was related to gangs and faith allegiances'', adding: "There was ongoing concern among some staff that a small minority of young people were being coerced into joining the Muslim faith.''

Andrew Cross, Feltham's governor, said he was working with chaplains and imams to combat forced conversions and extremism. The inspectors also criticised the use of force by officers, reporting that ethnic minority inmates were more concerned about safety than their white counterparts.

Ms Owers said Feltham still needed more external support to ensure it provided a "stable environment'' for inmates and called for improvements to the care of inmates with mental health problems.

She also complained about general standards of health care, with one young inmate being forced to wait six weeks for treatment to an injured finger which eventually became untreatable.

Phil Wheatley, director general of the Prison Service, said: "Feltham is a difficult establishment which manages some of the most disturbed and challenging young offenders in the country. Many suffer from mental illness and are abusers of hard drugs.

"In addition to this, Feltham has been under a considerable degree of public scrutiny and outside pressures for much of the past five years.

"Despite these considerable challenges Feltham is, without doubt, an improving prison that has made great progress in recent years.''

A judicial inquiry is under way into Mr Mubarek's death. The findings are due to be released next year.