Too little is being done to identify the signs of radicalisation and extremism in independent faith schools, Ofsted has warned.
The education watchdog today published a letter on the quality of inspections and reports by the Bridge Schools Inspectorate (BSI) - the body responsible for inspecting independent faith schools that are members of the Association of Muslim Schools UK or the Christian Schools' Trust.
In a letter from Ofsted chief Sir Michael Wilshaw to the BSI's chief inspector, the report criticised the BSI for not ensuring its inspectors could properly identify warning signs of extremism and radicalisation.
Ofsted staff found inspectors failed to go far enough in verifying whether schools' arrangements for safeguarding pupils are effective.
The report noted: "Inspectors did not evaluate evidence about students' spiritual, moral and social education in enough depth.
"Some inspectors did not demonstrate sufficient knowledge of ways to root out extremist behaviour, views and practices."
It said inspectors at times rely too heavily on the comments of school leaders and not enough on substantial evidence.
While the BSI's lead inspectors prepare their teams effectively, Ofsted said the quality of the school inspection it shadowed required improvement.
It said that while there were strengths within many of the inspectors' records, two documents showed "no evidence" of assessing whether pupils understand how to stay safe online.
During the last academic year, the BSI carried out 14 inspections. Ofsted's inspectors monitored one on-site inspection and reviewed three evidence bases and three inspection reports.
Ofsted judged the quality of the inspectorate's work was less strong than in previous years.
The watchdog recommended that the BSI's inspectors "probe deeply into how schools prevent extremism and radicalisation" as well as inspecting schools' safeguarding arrangements thoroughly, especially internet safety.