LONDON — The British government advised its citizens Wednesday to avoid travelling to Toronto, hours after the World Health Organization issued similar advice because of the infectious disease SARS.

Toronto joined Hong Kong, Beijing and the Chinese provinces of Guangdong and Shanxi on the British travel list.

Sir Liam Donaldson, Britain's chief medical officer, said the decision to issue the travel advisory was based on the WHO announcement and his department's own assessment of that advice regarding severe acute respiratory syndrome.

"The disease is caused by a new strain of a known family of viruses," he said. "This is a common way for new virus infections to emerge and like dozens of others there is no immediate prospect of it being eradicated."

Numerous other countries, such as Australia, Ireland and Jamaica, have issued similar travel advisories regarding travel to Toronto as well as parts of China.

Britain has reported six cases of SARS, and all but one of the people who have contracted the disease have been released from hospital.

At a boarding school in Somerset, 16 overseas students have been placed in quarantine as a precaution. The students are being separated from others for 10 days after returning from Easter holiday trips to China and Hong Kong.

Donaldson said he doesn't think there is a need for a wider quarantine of people travelling from infected parts of the world, believing instead that the travel advisory is the best precaution.

"This is the correct approach at the present time and expert advice does not recommend the mass quarantining of travellers returning from the Far East or Canada," he added.

"It is likely that it (SARS) will take its place as one of a range of known infections which cause serious outbreaks in different parts of the world which will need to be tackled."

Donaldson said the British Department of Health is in daily contact with medical experts at the WHO, other European countries, the United States and Canada as it assesses how to react to the disease.

"Everything that needs to be done in this country is being done and the risk of acquiring the infection in the United Kingdom at the present time is very low," he said.

"However, the way that SARS will progress is not predictable so that if there is any change to the SARS situation here we will not hesitate to take any necessary further action."