The Australian state of Victoria has entered its third lockdown since the Covid-19 pandemic began.
Premier Daniel Andrews issued the order to send the state into a "short, sharp blast" of lockdown to try to keep a third coronavirus wave at bay after a Covid-19 outbreak linked to the Melbourne Airport Holiday Inn quarantine facility grew to 13 cases.
Andrews said the lockdown was required because some of the new cases had the UK strain, which was "hyper-infectious" and posed a huge problems for the state's contact tracing effort.
"We are having cases test positive - and in rapid time we get notified of that positive test result - by the time we find that case as positive, they've already infected their close contacts," he said. "It is moving at a velocity that has not been seen anywhere in our country over the course of these last 12 months."
As of 11.59pm (local time) yesterday, and for the next five days, Victorians will only be able to leave their home for four reasons: essential shopping, care and caregiving, exercise, and essential work.
Hundreds of people protested in the city's CBD before the lockdown kicked in, with anti-lockdown protesters and mounted police gathering outside Melbourne Park.
Chaos gripped the Australian Open as fans were evicted midway through Novak Djokovic's match against American Taylor Fritz, with a chorus of boos heard as they were told to leave Rod Laver Arena at 11.30pm.
Overnight, Victoria added seven venues to an exposure site list that now includes two bus routes, a train and Melbourne's Terminal 4 as the cluster linked to the quarantine hotel grows.
The lockdown has an end date of 11.59pm on Wednesday, February 17 but boxed-in residents, who have had their hopes of an end to restrictions dashed in the past, will be watching and waiting to see what transpires between now and then.
Chief medical officer Professor Paul Kelly has now declared the Greater Melbourne area a Covid-19 hotspot for an initial period of three days. He said this was because of "the increased risk posed by the B117 [UK] variant of concern, the occurrence of cases in the community whilst infectious, and the risk of spread to other jurisdictions in Australia".
Genomic sequencing has already confirmed eight of the 13 cases of the Holiday Inn cluster are the highly contagious B117 variant, but authorities are working with the theory that all of the cases are that strain.
Andrews said he was confident that the imposed restrictions would be effective. "We will be able to smother this," he said yesterday. "We will be able to prevent it getting away from us."
Anti-lockdown protesters gathered outside the Australian Open in Melbourne Park on Friday night, hours before the lockdown was due to kick in.
Police were at the scene including a line of officers and some mounted officers as hundreds marched through the CBD.
Some of the crowd were holding signs reading "Victoria Says No", "Masks Are Muzzles" and "Australia Open, Victoria Closed".
In video of the protest shared on Facebook, captioned "Victorians are sick of lockdowns", protesters could be hearing singing lines from Twister Sister's "We're Not Gonna Take It".
When asked about the planned protest earlier on Friday, Andrews told 3AW Melbourne: "Is that like a vaccine, is it? It's going to suddenly fix everything? No, it's not. It might well spread the virus, though."
The Australian Open had been allowing crowds of up to 30,000, but those ceased at midnight.
Gatherings are not permitted under the new rules.
"I know it's not the news that Victorians want to hear today. I know it's not the place that we wanted to be in," Andrews said yesterday. "However, we've all given so much, we've all done so much. We've built something precious, and we have to make difficult decisions, and do difficult things, in order to defend what we've built."
text by Natalie Brown, news.com.au