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.

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, and many silent sources still exist within the area," a source was quoted as saying.

The government will only lift the lockdown declaration when it is satisfied everyone in the lockdown area has been tested, the paper said.