The head of the World Health Organization has expressed concerns over a new wave of coronavirus infections in South Korea and China reports NHK.

South Korea has confirmed a cluster of new infections involving people who visited nightclubs in Seoul on May 2.In the Chinese city of Wuhan, a new case was also confirmed on Saturday for the first time in about a month.

At a regular news conference on Monday, WHO Director-General Tedros Adhanom Ghebreyesus expressed concerns about the resurgence of cases in countries where the number of new infections had appeared to be decreasing.

He said that "early serological studies reflect that a relatively low percentage of the population has antibodies to COVID-19, which means most of the population is still susceptible to the virus."

He stressed the need to continue with a comprehensive package of measures such as detection, isolation of people infected with the virus and social distancing.

WHO principal legal officer Steven Solomon referred to a bid by Taiwan, which does not have member status, to participate in the organization's annual assembly next week as an observer.

Solomon suggested that the WHO chief cannot invite Taiwan to observe the meeting, but that member states can decide who attends the assembly.