Image caption The report was published jointly with the Youth Justice Board

Muslims made up of a fifth of all males in young offender institutions last year, a rise of eight percentage points in two years, says a report.

Some 21% identified themselves as Muslim in 2011-12, compared with 13% in 2009-10 and 16% in 2010-11, the report by the chief inspector of prisons said.

The total number of young people in custody fell by 14% last year.

Some 1,543 teenagers, aged 15 to 18, were held by the end of 2011-12, compared with 1,822 the previous year.

Around half (53%) said it was their first time in custody.

The decreasing size of the population has allowed 231 young offender places to be decommissioned.

The annual review of children and young people in custody, published jointly with the Youth Justice Board (YJB), also showed the proportion of those in custody from black and minority ethnic communities rose slightly to 42%, from 39% in 2010-11.

Men victimised

The chief inspector of prisons, Nick Hardwick, has called for young people's perceptions of their experiences in custody to help shape youth justice policy.

He voiced concern after a study found the proportion of young people who had felt unsafe at some time in custody had risen from 27% in 2010-11 to 32% last year.

The study was based on the experience of 926 young men in eight male establishments and 25 young women in three female establishments in which they were held from April 1, 2011 to March 31, 2012.

A quarter (25%) of young people said they had been victimised by another young person and 23% said they had been victimised by a member of staff.

Only 56% felt that they would be able to tell someone they had been victimised and just 28% felt it would be taken seriously if reported.

Meanwhile, almost a third (30%) said they had previously been looked after by a local authority.

Safety and welfare

Mr Hardwick said the figure was "depressingly high" and "reflected the over-representation of children from care in almost every indicator of disadvantage for decades".

"It might have been expected that reductions in the number of young people held and changes to the custodial estate would have led to changes of similar significance to young people's perceptions of their experience in custody," he said.

"In fact, it is striking how little has changed and that may cast doubt on the assumption that, as the population decreased, it would include a greater concentration of young people with a serious offence background and major problems."

The YJB was set up in 1997 to oversee the youth justice system and ensure that under-18s in custody were kept in safe conditions.

YJB chair Frances Done said the report is commissioned each year to help identify the progress made and areas which need further improvement.

"Children in custody are amongst those with the very greatest needs and and their safety and welfare is our highest priority.

"We will review the findings of this report and work with our secure establishments to ensure that they are taken into account in all aspects of their work."