Australia's Victoria, home to nearly 7 million people, was plunged into its sixth lockdown just weeks after exiting its last, as six locally acquired cases of COVID-19 were detected in the state on Friday, a day after several unlinked new infections in Melbourne suddenly emerged.

Lockdowns have been enforced across the east coast, including Australia's three largest cities — Sydney, Melbourne and Brisbane — putting more than 60% of the country's 25 million population under strict stay-home orders.