South Australia has reached a "pivotal day" in its fight to head off a second wave of coronavirus infections, with rising concern over a cluster of new cases.
Two new positive tests were reported on Tuesday, one involving a woman in her 20s linked to the emerging cluster centred on Adelaide's inner-northern suburbs.
The second case also involved a woman in her 20s but remained under investigation.
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 August 1, Agha Juice House in Blair Athol at 5-7.30pm on July 31 and Najafi Carpet Gallery in Kilburn at 5-8pm on July 29.
It also extends to two schools and a suburban hotel but those people are not required to self-isolate unless they develop symptoms.
The new infections took to 11 the number of new cases in the past 11 days with 10 of those still considered active.
There have now been a total of 457 COVID-19 cases since the start of the pandemic.
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 came as South Australia prepared to reimpose some virus restrictions including tighter limits on family gatherings, with no more than 10 people allowed, and a requirement for pubs and restaurants and other licensed venues to have all patrons seated.
The state is looking at 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 prevent anyone from entering unless they are an essential traveller, and the quarantine requirement for anyone arriving from NSW or the ACT.
Two men faced Adelaide Magistrates Court on Tuesday charged in relation to breaching those border measures.
Amin Derakhshan was accused of sneaking around a Victorian border checkpoint and Raza Rezai was accused of breaching quarantine orders five times after returning from interstate.
Both were refused bail and remanded in custody.
Australian Associated Press