South Australia has reached a "pivotal day" in its fight to head off a second wave of coronavirus infections, with a cluster of cases affecting Adelaide's northern suburbs.
As two new cases were reported on Tuesday, SA Health issued an alert for anyone who visited a fitness centre, a juice bar and a retail carpet outlet on various days last week, urging them to self-isolate and get tested if they develop symptoms.
The alert applies to anyone who visited Fernwood Fitness Centre in Salisbury Downs at 6-8.30pm on 1 August, Agha Juice House in Blair Athol at 5-7.30pm on 31 July and Najafi Carpet Gallery in Kilburn at 5-8pm on 29 July.
The alert also extends to two schools and a suburban hotel but those people are not required to self-isolate unless they develop symptoms.
SA's two new cases took the number of new infections to to 11 in as many days.
Chief public health officer Nicola Spurrier said it was important for everyone to do everything possible to reduce community transmission related to the growing cluster "before it gets away from us".
"Yesterday and today have really been very concerning for my team," she said.
"You could say it's a pivotal day."
The concerning cluster comes as SA prepares to reimpose some virus restrictions including tighter limits on family gatherings, with no more than 10 people allowed, and a requirement for all pubs and restaurants to have all patrons seated.
The state is looking at all density requirements, which currently require only two square metres for each person, and is likely to cut the number of people at AFL games from about 20,000 to about 10,000.
SA is also keeping its tough border measures with Victoria in place, which prevents anyone entering unless they are an essential traveller, and the quarantine requirement for anyone arriving from NSW or the ACT.
An Adelaide man was due to face court on Tuesday for breaching the border rules.
Police allege the 31-year-old attempted to enter SA from Victoria at a Pinnaroo border checkpoint on Sunday but was turned away because he did not meet the essential traveller status.
He returned to the checkpoint 30 minutes later and was again refused entry.
However, police said the man did not return to Victoria but filled up with fuel at a nearby service station before travelling into metropolitan Adelaide.
Police further allege that since the start of April, the man breached directions of the Emergency Management Act on seven other occasions.
