Another of the Government's flagship free schools has been ordered to improve by inspectors amid concerns about its teaching, leadership and pupil performance.
Nishkam Primary School in Birmingham has been judged to "require improvement" by Ofsted following an inspection last month.
It is the fourth free school out of those inspected so far to have been handed the rating, and now faces another visit from the watchdog within two years.
The multi-faith school, which is described as having a Sikh-ethos, attracted criticism from inspectors for its teaching, with bright pupils often set work that was too easy and a lack of interesting work to hold youngsters' attention.
Ofsted's report concluded that the school needed to raise its standards because "there is not enough teaching which is good enough to enable pupils to learn as quickly as they should".
It said: "Teaching does not enable all pupils to make good progress because work is not always set at the right level.
"In particular, more able pupils do not make good progress because they are frequently given work which is too easy.
"Marking does not give pupils clear guidance on how to improve their work. Consequently, they do not learn as quickly as they could.
"Teaching does not always interest the pupils enough. When this happens, they quickly become distracted and do not always behave well enough. This slows the pace of learning."
Inspectors were also critical of the school's leadership, suggesting that the leaders and governors did not have a clear understanding of the school's strengths and weaknesses.
Ofsted said children got off to a good start in Reception, and that disabled pupils and those with special educational needs made good progress.
It also praised the school for making pupils feel safe and secure, and for helping to develop pupils' spiritual, moral, social and cultural education.
Overall, inspectors rated Nishkam Primary as requiring improvement in all of the main areas its examines - achievement of pupils, quality of teaching, behaviour and safety of pupils and leadership and management.
"Requires improvement" is the third of Ofsted's ratings, below "outstanding" and "good", and one above "inadequate".
The school was one of the first 24 free schools to open in 2011. So far, 13 of these have had Ofsted reports published.
The latest, published today, was ARK Conway Primary School in Hammersmith, west London, which was judged outstanding by inspectors - the first free school to receive this rating.
A total of seven free schools have been rated good, three alongside Nishkam Primary have been found to require improvement - these are Batley Grammar in West Yorkshire, Kings Science Academy in Bradford and Sandbach School in Cheshire - and one - Discovery New School in West Sussex - was found to be inadequate.
ARK Conway Primary School which was also one of the first 24 free schools, was praised by inspectors who said that its "high quality teaching inspires and motivates all pupils to try their very best".
The Ofsted report said that teachers at the school set high expectations for learning and behaviour that pupils respond to "extremely well" and that youngsters achieve highly, particularly in learning to read and write and in maths.
Headteacher Damian McBeath said: "We are delighted that the hard work and dedication of staff, parents and pupils have been recognised by Ofsted. The academy has only been open since September 2011 and from the outset, we have focused on delivering the highest-quality education for our pupils. They are happy, inspired to learn and making incredible progress."
Education Secretary Michael Gove said that ARK Conway had shown how a school can be "truly excellent" within two years.
Free schools are independent, state-funded schools set up by groups including parents, teachers, faith groups and charities.
Mr Gove has previously said that these schools are "extremely popular with parents" and are "delivering strong discipline and teaching excellence across the country".
Some 55 free schools opened their doors last year, and about 200 are due to open from this September onwards.
Last month, Chancellor George Osborne announced that money has also been set aside to create 180 new free schools in 2015/16.
Mr Gove later added: "Free schools, set up by dedicated groups of individuals and organisations, are raising standards and giving parents a real choice of good local schools. More and more free schools are opening and I look forward to many more being rated outstanding over the coming years."