Authorities have moved to a put a "double ring" around a worrying cluster of coronavirus cases in Adelaide as they bid to head off any widespread community transmission.
Five cases are currently linked to the cluster which has closed the Thebarton Senior College, forcing 94 close contacts into supervised hotel quarantine.
More than 1100 other people, including fellow students and staff at the college and the family members of the close contacts, have been asked to isolate at home for 14 days.
Additionally, South Australian Opposition Leader Peter Malinauskas and his deputy Susan Close are also in home isolation after visiting the college last week.
Chief Public Health Officer Nicola Spurrier said the tactics with the Thebarton cluster mirrored those used successfully to control an outbreak of virus infections in northern Tasmania earlier this year by widening the scope of those being monitored.
"I am trying to put a double ring around this chain of transmission," Professor Spurrier said.
SA reported two new COVID-19 cases on Friday, but both involved people who returned from overseas this week on repatriation flights.
A woman in her 20s and a man in his 50s are in hotel quarantine and are only displaying mild symptoms.
Despite the new cases, the state's transition committee left all the current virus restrictions unchanged after reducing family gatherings to 10 earlier this week and wedding and funerals to 100.
However, in a move prompted by Victoria's high number of cases in aged care facilities, SA will test all aged care workers with any links to the Thebarton cluster as a further precaution.
"If we have an outbreak in an aged care facility, it is absolutely critical we get on top of it quickly," Prof Spurrier said.
Mr Malinauskas and Ms Close said they only met the principal of the Thebarton college and did not have contact with students or tour the facilities.
They followed all COVID-19 measures but on the advice of health authorities would isolate as a precaution.
"Thankfully we feel well and are currently not showing any symptoms but given SA Health's advice we have cancelled all face-to-face engagements next week and will self-isolate as per SA Health's direction," the pair said in a statement on Friday.
"Although this is an inconvenience, it is nothing in comparison to the heartache felt by so many South Australian's who currently find themselves out of work.
"It is vitally important we all do the right thing to ensure the type of outbreak being seen in Victoria doesn't happen here in South Australia."
Australian Associated Press