A Beijing children's hospital told state media CCTV that at least 7,000 patients were being admitted daily to the institution, far exceeding its capacity.

This week groups including the international Program for Monitoring Emerging Diseases (ProMED) reported clusters of undiagnosed pneumonia in children in north China.

“With the outbreak of pneumonia in China, children’s hospitals in Beijing, Liaoning and other places were overwhelmed with sick children, and schools and classes were on the verge of suspension. Parents questioned whether the authorities were covering up the epidemic,” ProMed was quoted by FTV news as saying.

Beijing responded to the WHO's request within 24 hours, in line with the organisation’s regulations, saying that it was "routine" to request information from member states.

“No changes in the disease presentation were reported by the Chinese health authorities,” the WHO said. It added that Chinese officials said the spike in patients had not overloaded the country’s hospitals. ■