Salespeople from countries affected by a highly contagious form of pneumonia have been banned from an international watch and jewellery fair in Switzerland later this week.
The government announced the ban on Tuesday as part of its measures to prevent the spread of Severe Acute Respiratory Syndrome (SARS).
The Federal Health Office said salespeople from China, Hong Kong, Vietnam and Singapore would not be allowed to man stands at the World Watch and Jewellery Show, which takes place simultaneously in Basel and Zurich.
Thomas Zeltner, the Office's director, said close contact between exhibitors and visitors could lead to SARS being transmitted at the fairs. He added that the decision had been taken after consultation with organisers and cantonal authorities.
According to the latest figures by the United Nations health agency, at least 63 people around the world have died from SARS so far and 2,000 others have been infected.
The announcement has dealt a severe blow to the fair's organisers, affecting some 350 - or one in six - of all exhibitors.
However, the government said there would be no ban on tourists from Hong Kong, China, Singapore and Vietnam planning to visit the fair.
Around 6,000 visitors and exhibitors from southeast Asia were expected to attend the week-long event, which opens on Thursday.
"Basel World" is one of world's largest luxury goods fairs. But organisers are bracing themselves for a drop in sales and visitor numbers as a result of the ongoing economic downturn and the war in Iraq.
Around 80,000 visitors are expected to attend this year's fair, 2,500 fewer than last year.
Following an extraordinary session called to discuss SARS, the government said it did not envisage imposing restrictions on people returning from the Far East for the time being.
Switzerland has also so far stopped short of issuing precautionary travel recommendations for Asia, but Zeltner said it might do so in the coming days, depending on how rapidly the disease was spreading.
The Federal Health Office said on Monday eight people in Switzerland had been treated for symptoms of the illness over the past few weeks, and that all but one patient had recovered.
swissinfo with agencies
At least 63 people worldwide have died from SARS, most of them in China.
Swiss authorities said they would issue a travel warning for Asia if the disease continued to spread.
The Federal Health Office has set up a hotline to deal with any enquiries regarding SARS.