China has told the World Health Organization that an increase in respiratory illnesses and clusters of child pneumonia is not caused by new or unusual pathogens.

In a statement released on Wednesday, the WHO said that since mid-October, northern China has reported a rise in influenza-like illness compared with the previous three years. It also cited data about child pneumonia from the International Society for Infectious Diseases.

Earlier this month, China's National Health Commission said cases of mycoplasma pneumonia had risen mainly in the country's north. It said people infected included children 3-years old and younger.

Chinese authorities have also noted a spread of flu cases. They say they need to enhance surveillance of infections including COVID-19.

The WHO held telephone talks with Chinese health authorities on Thursday.

During the talks, the Chinese side submitted data and said that they have not detected any new or unusual pathogens.

China said it is a general increase in respiratory diseases caused by already known pathogens.

Chinese authorities also explained that the increase in the number of patients has not exceeded hospital capacities.

The WHO says that based on the current information, restrictions on travel to China and trade with it are unnecessary.

The WHO also says that it will closely monitor the situation and keep in close contact with Chinese authorities to provide the latest information.