The four -- identified as three Asian tourists and an ambulance driver -- were kept in isolation at Edinburgh Royal Infirmary after they were admitted in the early hours of the morning.

But they were later released when it was determined that they were not suffering from Severe Acute Respiratory Syndrome (SARS), the illness that triggered a major public health scare in East Asia and Canada last year.

"They have all been given a clean bill of health and released," a spokeswoman for the National Health Service said. "This was a false alarm but we dealt with it using all necessary precautions."

TERRA.WIRE