China says it is investigating four new suspected cases of Severe Acute Respiratory Syndrome, or SARS, in its capital.
The Chinese Ministry of Health announced on its website Sunday that all of the new suspected cases have been traced back to a single patient, suggesting the problem was still tightly confined and not a general outbreak.
The disease killed 349 people in China during last year's outbreak.
The latest four cases brought the total in China for the past week to two confirmed and six suspected cases.