Australia's Queensland state on Monday reintroduced mandatory masks and limited home gatherings, adding to increasing social distancing restrictions around the country as it battles an outbreak of the coronavirus. Sydney, Australia's most populous city, was plunged into lockdown over the weekend, along with the northern city of Darwin, as officials grapple to contain outbreaks of the highly contagious Delta COVID-19 variant.

More than 10 million Australians, or two-fifths of the population, are now under some form of lockdown or COVID-related restrictions. Australia's national security committee is expected to hold an emergency meeting later on Monday to take stock of the growing crisis as new cases emerge across the country.

In Queensland, authorities urged residents in several local council areas, including state capital Brisbane, to wear masks even before the rule becomes effective from midnight Monday. Sydney began a two-week lockdown on Sunday to contain an outbreak of the highly contagious Delta virus variant.

Northern Territory capital Darwin and nearby areas entered a snap two-day lockdown on the same day to prevent a Delta cluster that has been linked to a worker at a gold mine. Western Australia reintroduced mandatory masks in indoor locations, and limited gatherings at homes and outdoors in state capital Perth for three days from Sunday after detecting a case linked to the Sydney cluster.

Australia has so far fared much better than many other developed countries in tackling the spread of the coronavirus, with just over 30,450 cases and 910 deaths. Lockdowns, tough social distancing rules and swift contact tracing have helped the country successfully suppress prior outbreaks but the fast moving Delta variant has alarmed health authorities.