A dozen people in Hong Kong who had recovered from severe acute respiratory syndrome have suffered relapses, according to medical authorities on Wednesday.

While the reported cases represent only a tiny fraction of more than 2,420 Sars patients already released from hospitals worldwide, they will raise fears that other survivors could still be carrying the virus and remain vulnerable to its effects.

The prospect of quick and complete recovery for the majority of Sars victims has been one of the greatest sources of comfort for health authorities, which have battled to contain its spread throughout the region.

Beijing, the current centre of the outbreak that began in southern China late last year, is already suffering shortages of hospital beds and medical equipment as new cases are reported at a rate of more than 100 a day.

Wang Qishan, the acting mayor of the Chinese capital, said on Wednesday the city government was moving fast to add capacity at new facilities.

"Due to a shortage of beds at designated hospitals, not all suspected Sars patients can be hospitalised in a timely manner," Mr Wang said at a news conference, where he stressed the seriousness of the challenge facing authorities and the need to alleviate panic among the public.

Mr Wang, whose predecessor was sacked this month after attempts to cover up the extent of Sars' spread, promised to provide more data on the outbreak and to work closely with World Health Organisation experts.

Taiwan on Wednesday confirmed that two health workers had died from Sars, raising the death toll on the island to three.

The news comes amid an outbreak among hospital staff that has sent the number of infections soaring from 27 to 78 in a week.

India said it had discovered 10 cases of Sars in spite of unprecedented efforts to prevent the virus from entering the country.

Meanwhile, a group of Air India pilots took the airline to court after it suspended them for refusing to fly with crews who had visited Sars-affected areas.

Gerhard Schröder, German chancellor, is to visit Malaysia, Singapore, Indonesia and Vietnam this month. Government officials confirmed the tour would go ahead but said he would not be accompanied by the planned 100-strong business delegation.