The World Health Organization (WHO) has asked China for more information on “clusters of undiagnosed pneumonia” reportedly spreading amongst children in the north of the country.
Non-state media reports say children’s hospitals in parts of the country are overwhelmed with sick children.
Chinese authorities have attributed a spike in flu-like illnesses this winter to the lifting of Covid measures.
The WHO is urging people in China to take measures to reduce transmission.
In a statement the UN health agency says it wants more information on reports in the media and from ProMed – a global outbreak surveillance system – of “clusters of undiagnosed pneumonia in children in northern China”.
Since October, northern China has reported an “increase in influenza-like illness” compared to the same period over the past three years, it adds.
Last week, China’s National Health Commission said there had been a rise in several respiratory diseases across the country – in particular influenza, Covid, mycoplasma pneumoniae – a common bacterial infection affecting younger children – and respiratory syncytial virus (RSV).
Officials attributed the rise to the lifting of Covid restrictions.
Other countries, including the UK and the US, saw similar surges in flu-like illnesses once pandemic restrictions were lifted.
The WHO says it is unclear if the reported pneumonia outbreak and overall increase in respiratory infections reported by Beijing are linked – and has made an official request for more detailed information.
It has urged people in China to take basic precautions like getting vaccinated, wearing masks and hand-washing.