Li Liming, director of Chinese Center for Disease Control and Prevention, has resigned after a laboratory in the center was confirmed as the source of the country's severe acute respiratory syndrome (SARS) outbreak earlier this year, official sources said Thursday.

Four of Li's colleagues were also disciplined due to the SARS virus infection of some staff members earlier this year, and a total of nine people were declared as SARS patients during April and May.

Poor management of the virus triggered the SARS outbreak in Beijing and Anhui Province in east China. The SARS recurrence has been determined as a case of major accident due to negligence, sources with the Chinese Ministry of Health said.

A 26 year-old girl surnamed Song was declared a diagnosed SARS patient in late April, and was presumed to have contracted the disease when serving as an intern at the Beijing-based Research Institute of Virus Diseases under the center from March 7 to 22.

Later on, Beijing and Anhui Province reported eight more SARS cases. The outbreak was contained at the end of May.