All resources used to teach about other faiths must be unbiased, says Ofsted
Independent faith schools must ensure all resources used to teach about other religions are accurate, inspectors say.
Ofsted surveyed 51 schools in England from the Christian, Jewish, Muslim, Buddhist and Hindu faiths, at the request of Schools Secretary Ed Balls.
Inspectors said some materials were biased or had incorrect information about the beliefs of other religions.
But the schools were judged to be good at helping pupils understand the importance of being a good citizen.
The private schools - both primary and secondary - were also judged good at providing for pupils' spiritual, moral, social and cultural development.
All "worked hard" to develop pupils' personal confidence to deal with negative influences, such as anti-Semitism, without compromising their beliefs and included respect for other cultures and faiths.
"Pupils gained a strong sense of personal worth and of belonging to their faith community," the report said.
But inspectors raised concerns about some of the teaching materials being used, particularly in relation to other faiths.
In most cases, they said the materials on display and books used were "balanced in terms of tone and content".
"There were, however, instances of displays of teaching materials in eight of the schools that had a bias in favour of one group," the report said.
"For example, wording used to describe the situation in Palestine, seen in a Muslim school, used inflammatory language.
"Similarly, in a Jewish school, pupils' writing used strong language in describing situations in that part of the world.
"Some of the published teaching materials seen contained biased or incorrect information about the beliefs of other religions. "
Moving to secular schools
The report found some pupils struggled with the transition from independent faith primary schools to secular secondary schools.
Inspectors found some children felt forced to compromise parts of their everyday religious practices.
Some parents felt schools were reluctant to provide a place for pupils to pray, with one questioning why a state school could provide a space during Ramadan, but not the rest of the year.
The majority of the schools were happy to participate in the Ofsted survey, but two expressed concerns about being "continually under scrutiny".
Executive director of Ofsted, Miriam Rosen, said: "All schools have an important role in preparing their pupils for life in modern Britain.
"Our inspectors found that in these independent faith schools, pupils gained a strong sense of identity and of belonging to their faith, their school and to Britain."
Mr Balls, who commissioned the report in March, said: "It is vital that all schools, including faith schools, continue to work hard to promote high standards and give all pupils the opportunity to learn about different cultures and faiths.
"This report shows many good examples of schools using objective and accurate materials, but I urge all schools - faith or otherwise - to make sure the materials they use help pupils develop a good understanding of different faiths and cultures."