The schools are refusing to re-admit pupils until they have spent 10 days in isolation to check they are not infected with the disease.

Around 4000 pupils from Hong Kong and Singapore attend independent schools in the UK. Many returned home for the Easter holiday and are due to fly back to Britain from Friday. But pressure from anxious British and European parents, who fear their children could catch the infection from classmates, has forced some schools to insist on a quarantine period for pupils returning from South East Asia.

A guardianship agency, providing UK guardians for pupils whose parents live abroad, has taken over two holiday camps on the south coast of England to run as quarantine units from April 18. So far 200 pupils are signed up for the camps.

Duncan Hume, owner of the White House Guardianships agency, has organised the camps on behalf of his trade body, the Association of Guardianship Services.

He said: 'We have hired two units on the south coast. They are holiday camps. We will collect the students and take them down there for a 10 day holiday. We are advising students to bring loads of books with them to study because their exams are coming up. The schools are also sending work for them. It will be a mixture of study and activities.'

Hume said the camps have been set up at the insistence of parents of British pupils and not on the advice of public health experts.

'The official line from the Public Health Laboratory Service is that there is no need to isolate young people. But some schools are asking for a 10 day isolation period because other parents fear Sars.

'The reaction is from British parents. They want to know if their child is going to be sharing a dormitory with someone who is just back from Hong Kong. One headmaster said to me: 'I am doing this to shut the British parents up'.

'We could not ask guardianship families to take these pupils. They would say they had an elderly relative or a young child and couldn't put them at risk. This is the plan we came up with. It is not ideal.'

Policies differ between boarding schools. Some are insisting on quarantine while others are allowing pupils to begin term as usual, provided they have a medical check before they leave the Sars affected area and another when they arrive in the UK. They will then be admitted to the school but checked for symptoms twice a day.

A statement issued by the Hong Kong Economic and Trade Office, based in London, said: 'Parents should be aware that some independent schools in the UK are advising parents that children should return to the UK 10 days before the start of the term to check their health during the likely incubation period. Independent schools each have different policies on how they will handle students returning from Sars areas.

'For this reason parents are advised to contact individual schools directly to see what the school's policy will be.'

Fettes College in Edinburgh says it is not insisting on quarantine but is asking parents to send children back 10 days before the term starts to check they are free of the virus.

A spokesman for the college, which has 75 pupils from South East Asia, said: 'We have suggested to parents that the best thing they could do, if they have children from affected areas, is to get those children back 10 days before the term starts. We have suggested this might be better than having the children monitored once the term has started. This would allow the period of monitoring and incubation to be over before the school term starts.' But Merchiston Castle School, also in Edinburgh, is inviting pupils from Hong Kong and Singapore to return at the same time as fellow classmates.

Headmaster Andrew Hunter said that insisting on quarantine for pupils who had shown no symptoms of Sars could even be discriminatory.

'A key concern is the interests of all pupils and parents from Scotland and the UK but we have to be careful about insisting on something that does not stand up medically and could be discriminatory. There is no need to quarantine pupils just because they have travelled from affected areas.'