Hong Kong will place tens of thousands of its residents in a lockdown to contain a new outbreak of the coronavirus, the first such measure the Chinese-ruled city has taken since the pandemic began, a local newspaper reported on Friday.

South China Morning Post, citing unnamed sources familiar with the situation, said the new measure will target the Jordan and Sham Shui Po districts which cover a small, but densely populated part of the Kowloon Peninsula.

The districts are home to many ageing, subdivided flats in which the virus could spread more easily.

"Persistently high and spreading infection [in the areas] and sewage surveillance suggest the outbreak is not yet under control...