PA -- London is "sleepwalking" towards apartheid, a private school head has warned.
David Levin, headmaster of City of London School, said he was "increasingly alarmed" that the capital has become divided into "ghettos".
Speaking at the Headmasters' and Headmistresses' Conference (HMC) annual meeting in St Andrews, Mr Levin said: "I grew up in South Africa, where apartheid was imposed by the government. People had to live in different areas.
"Increasingly, I am alarmed at the way London is divided into ghettos. We've become a silo society."
He cited Stepney Green Maths and Computing and Science College, a boys' school in Tower Hamlets in east London, where 97% of pupils are from a Bangladeshi background.
"A number of those children, through no fault of their own haven't been outside their council estate let alone outside Tower Hamlets. This cannot be a good thing," he said.
Mr Levin said his school runs a gifted and talented programme with GCSE pupils from this school. He added that another school he has links with in Peckham, south London, is "overwhelmingly" west African. "In my view I think London is sleepwalking towards Johannesburg. The ghettoisation of the communities."
This has an impact on pupils, Mr Levin suggested: "It means that they are not mixing with other people from different faiths, different races and different socio-economic backgrounds.
"One of the things I have certainly learned particularly pre, and post-apartheid is that your imagination is much stronger than the reality.
"You may not like someone, but if you know them you do not fear them and I think schools should be an area in which in a rational protected way, children from a different background, faith, racial grouping should come together in a common purpose of education and get to know each other. I think that's very important."