The spread of influenza and other respiratory infectious illnesses has been increasing in recent weeks across China, the Chinese Center for Disease Control and Prevention said on Thursday.

Some provinces are already experiencing low to moderate levels of flu activity, according to the China CDC.

During the past week, the H3N2 subtype of influenza A accounted for over 90 percent of all positive flu virus samples collected in both southern and northern provinces.

READ MORE: Risk of infectious diseases over May Day holiday, warns China CDC

"Surveillance data shows that all respiratory infectious illnesses during this period were caused by known, common pathogens, with no unknown or emerging viruses identified," the center said.

It highlighted that the positivity rates of enterovirus, rhinovirus, and respiratory syncytial virus have also been increasing or maintaining high levels, adding that the prevalence of the novel coronavirus and other respiratory pathogens remains low.

The China CDC is urging prompt response measures to these outbreaks and advising the public to get flu vaccinations, wear masks when necessary, and maintain good personal hygiene.