Three northern towns which suffered race riots two years ago dominate a new analysis of the most segregated schooling systems in England.
A study of 150 local education authorities found Oldham and Bradford among the top five councils ranked according to the degree to which Asians and non-Asians were schooled separately.
Blackburn-with-Darwen, which borders Burnley where there was also rioting, was also in the top five. On one measure, these three authorities ranked one, two and three for segregation.
The researchers say the findings suggest an association between educational segregation and social unrest, but admit figures may simply reflect racially divided housing in the towns.
Academics from the Leverhulme Centre for Market and Public Organisation at Bristol University used two measures, based on information from the annual schools census for 2001, to assess racial segregation.
A "dissimilarity index" assessed the proportion of pupils of a particular racial group who would have to move school in order for all schools in the area to have similar proportions of pupils from that group.
An "isolation index" assessed the probability of meeting a student from the same racial group in each school: this would be lower in authorities with very mixed schools.
Among Asian pupils, Oldham, Blackburn and Bradford were the three top-scoring authorities on isolation.
The researchers found pupils of Asian origin were more segregated than African, Caribbean or other black pupils.
Authorities with high proportions of black pupils tended to have more mixed schools but the reverse was true for Asian pupils.
The study described the overall level of segregation in England's schools as "high". For example, on average, half of the Asian pupils in each local authority would have to move school to create an even distribution of such pupils throughout an authority. For black pupils, this figure was slightly lower.
The research team plans to carry out further work on whether schooling accentuates the effect of housing segregation and whether policies allowing parents to choose schools have contributed to segregation.
David Ward, a Liberal Democrat councillor on Lib Dem-controlled Bradford council, said that segregation was bound to exist when housing was largely divided on ethnic lines. The only way to guarantee mixing was to bus children to different schools around the city, which had been tried and failed 20 years ago.
But the council was addressing the issue partly by twinning 20 primary schools educating mainly non-white pupils with 20 which have a predominantly white intake.
At secondary level, collaboration between schools intent on offering pupils greater subject choice was also breaking down barriers.
Mr Ward added: "We know what the problems are in Bradford and we are determined to deal with them."
BNP governor 14