BEIJING, Jan. 13 (Xinhua) -- The COVID-19 patients infected during the recent outbreak in north China's Hebei Province have an average age of 50, a health official said Wednesday.

About 30 percent of Hebei's patients are over 60 years old, said Guo Yanhong, an official with the National Health Commission, at a press conference.

Sporadic and clustered COVID-19 cases have been reported in some regions recently, Guo said, noting that many of the patients are aged and live in rural areas.

In northeast China's Liaoning Province, where clusters of cases were also reported recently, the average age of patients was 53, with 37 percent over 60 years old, according to Guo.

Noting the challenges faced in the rescue and treatment work, Guo said critically ill patients in Hebei and Liaoning are currently in stable condition.