The World Health Organisation has asked China for more detailed information about an outbreak of a respiratory illness and reported clusters of undiagnosed pneumonia in children,Sly News reported.
Since mid-October, the WHO said northern China had reported an increase in influenza-like illnesses compared with the same period in the previous three years.
In recent days, local media in cities such as Xian in the northwest have posted videos online of hospitals crowded with parents and children waiting to be seen by medics.
The WHO has responded by making an official request to China for additional information as well as laboratory results from the reported outbreaks among children.
In the meantime it has been recommended that Chinese communities take preventative measures including getting vaccinated, wearing masks, keeping a distance from sick people, staying at home when ill and regular hand-washing.