BEIJING, May 13 (Xinhua) -- China's risk of COVID-19 cluster infections caused by sporadic cases cannot be ignored although the epidemic is in a generally stable state in the country at the moment, a health official said Wednesday.

The newly reported six confirmed domestically transmitted cases in the Chinese mainland on Tuesday were all related to previous cluster infections, said Song Shuli, a spokesperson for the National Health Commission, at a press conference in Beijing.

"We need to stay alert and put in place measures for regular epidemic response to resolutely prevent new outbreaks," she added.