More than 100 cases of the novel coronavirus have been officially recorded, in the fresh outbreak in Beijing, the World Health Organisation said on Monday.

As lockdown restrictions ease and countries in Europe lifted their borders, the WHO warned countries to stay on alert for a possible resurgence of Covid-19 infections.

WHO said it understood no new deaths have been reported thus far in the Chinese capital, but added that given Beijing's size and connectivity, the outbreak was a cause for concern.

In a virtual press conference, WHO director-general Tedros Adhanom Ghebreyesus said even in countries that have demonstrated the ability to suppress transmission, countries must stay alert to the possibility of resurgence.

The virus first emerged in Wuhan in China in December last year, and it since drove local transmission down to near-zero as the crisis hammered the rest of the world.