Johannesburg: A popular South African private school firm on Friday denied charges of racially segregating classrooms, saying it sometimes separates children based on culture, a policy that has provoked public anger 20 years after the end of apartheid.

A group of around 30 parents signed a petition this week against what they said was racial segregation at the Curro Foundation School in Roodeplaat, a town near Pretoria, according to local media reports.

The school is one of more than 40 run by Cape Town-based Curro Holdings, which has seen explosive growth since listing on the Johannesburg exchange in 2011, reflecting surging demand for private education from a growing black middle class.

Curro chief executive Chris Van Der Merwe told Talk Radio 702 the school did not separate students based on race.

“This is not so simple as referring to a policy of segregation. Just to remind the folks and supporters that we don’t stand for segregation, not at all,” Van Der Merwe said, adding that two-thirds of its 36,000 students were black.

However, he said that in year-groups with a small number of white children, the white students were sometimes kept together in a group to help them make friends within their own “culture”.

As soon as there were 12 white children, they were divided evenly between classrooms, he said.

Van Der Merwe also said that apparent racial separation may be a consequence of choice of language — white Afrikaans parents are likely to opt for tuition in Afrikaans, a language that few black parents are likely to choose.

Race in education remains an emotive issue in South Africa.

Under white minority rule, which ended in 1994, blacks were relegated to substandard government schools designed to prepare them for little more than unskilled, manual labour.

South Africa’s public education is ranked among the worst in the world by the World Economic Forum, prompting many middle class parents to turn to private schools such as those run by Curro.

Since listing, Curro’s share price has increased more than sevenfold. Its shares were little changed at 32.80 rand (Dh10) in early trade on Friday.

Education department inspectors are due to visit the Roodeplaat school on Friday.