A week after China began dismantling its tough 'zero-COVID' controls, the World Health Organization warned of "very tough" times ahead and state media reported some seriously ill patients at hospitals in Beijing, raising fears of a wave of infections.

China should change its official name for COVID-19 to reflect the virus' mutation, and patients with light symptoms should be allowed to quarantine at home, a leading authority on traditional Chinese medicine was quoted as saying on Wednesday.

China's financial hub Shanghai said on Sunday it would reopen all schools including kindergartens, primary and middle schools on Sept. 1 after months of COVID-19 closures.