Around 300,000 people in Melbourne have been placed back in lockdown following a spike of coronavirus cases in the Australian city.
Two weeks of double-digit rises in COVID-19 cases have stoked fears that a second wave of the disease is on its way.
It comes as the UK introduced the first local lockdown in Leicester after a spike in positive tests of the illness.
Health secretary Matt Hancock announced the extended restrictions this week – coming ahead of the reopening of bars and restaurants across the rest of England over the weekend.
Australia has fared better than many countries in the pandemic, with around 7,830 cases and 104 deaths.
However, more than 30 suburbs in Melbourne – Australia’s second-biggest city – will return to stage 3 restrictions, the third-strictest level in curbs to control the pandemic.
Residents will be confined to their homes and only allowed out for grocery shopping, health appointments, work or caregiving, and exercise.
The state of Victoria recorded 73 fresh cases on Tuesday from 20,682 tests, following an increase of 75 cases on Monday.
State premier Daniel Andrews warned on Wednesday that the return of broader restrictions across city remained a possibility.
He said: ”If we all stick together these next four weeks, we can regain control of that community transmission… across metropolitan Melbourne.
"Ultimately if I didn't shut down those postcodes I'd be shutting down all postcodes. We want to avoid that."
Australia is not the only country to have seen a spike in coronavirus cases.
Some US states – most notably Texas, Utah, Arkansas and Arizona – have all seen a surge, while Germany has seen a handful of significant outbreaks at meat-processing plants in recent weeks, forcing officials to reintroduce lockdowns.
Brazil and India have also seen huge spikes – with Brazil now having the second-highest number of coronavirus cases in the world, according to Johns Hopkins.
Global coronavirus cases exceeded 10 million on Sunday, while more than half a million have died from the illness, in just seven months.
Boris Johnson has been accused of being slow to respond to the coronavirus outbreak in Leicester, resulting in the city being forced into a local lockdown.
Labour leader Sir Keir Starmer accused the prime minister of presiding over a "lost week" when action could have been taken, in the first real test of Johnson's "whack-a-mole" strategy for tackling coronavirus clusters.
The PM insisted action had been taken swiftly and defended the sharing of testing figures with local leaders.
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