A controversial secure children's training centre should temporarily close, according to a watchdog.
Anne Owers: Called for temporary closure
Chief prisons inspector Anne Owers said an inspection of Oakhill near Milton Keynes had found a "staggering" level of force being used against children.
The report said staff had used force 400 times and suffered 200 assaults last summer at the private centre.
The Youth Justice Board said inspectors had not called for closure when they had first reported back.
The secure training centre is one of four used to hold young offenders aged between 12 and 17 years old. Children held in STCs are usually among the most troubled and violent youngsters in the criminal justice system.
In an unusual move, the Youth Justice Board asked the prisons watchdog and Ofsted, the educational standards watchdog, to jointly inspect the centre in October 2007.
The report found that in the nine months before the inspection, force had been used 757 times. On 532 occasions this had involved the highest level of restraint, which requires three members of staff.
Three children in the centre were said to be responsible for 40% of all violent incidents taking place in one week.
In turn, staff were said to lack confidence and were resorting to force to exert control over the children. Inspectors said the annual turnover of staff was running at 59%.
"At the time of the inspection, we found the staff at the centre continued to struggle to maintain order and control safely the children in their care, though a new director was beginning to get to grips with the task," said Ms Owers.
"There was an over-reliance on emergency measures - in particular, a staggeringly high level of use of force by staff, often in response to assaults by young people.
"While we welcomed some early signs of improvement, we considered that the scale of the task was daunting, and that it might be more realistic to empty the centre briefly so that it can be re-launched."
Christine Gilbert, head of Ofsted, added the standards of education and training at the centre remained inadequate - but that welfare of those being held was "satisfactory".
"Oakhill has had a very difficult history since opening in 2004," she said.
"The quality of teaching, the suitability and breadth of the curriculum, the effectiveness of behaviour management, and leadership and management are all found to be inadequate.
"However there are some early signs that the new director has started to make improvements to address the concerns and it is hoped that these will continue."
A spokesman for the Youth Justice Board said Ms Owers' call for a temporarily closure of the centre had not figured in a meeting with inspectors, following their visit.
The number of children being held at Oakhill had been cut to below 60 and had been allowed to run as low as the 30s to assist the new director in overhauling conditions, said the spokesman. A monitor was also on site to oversee changes.