Since SA opened its borders to all states and territories in November, some problems have emerged with reports of travellers being taken to hotel quarantine when they expected to isolate at home.

The new Omicron variant of the virus has also prompted authorities to increase quarantine for people returning from overseas from seven to 14 days.

Premier Steven Marshall said while not everything could always be handled "100 per cent correctly", overall the state had managed the pandemic and the imposition of restrictions well.

"South Australia is the safest state in the safest continent. We have handled it extraordinarily well," the premier said.

"If there have been any issues that have inconvenienced people, we apologise.

"But our primary responsibility is to keep our state safe and our economy strong."

The premier's comments on Wednesday came as SA Health reported three new coronavirus cases.

One was linked to the so-called Norwood cluster, taking it to 28 with the two others detected in overseas and interstate arrivals.

The state currently has 46 active infections with two people, a woman in her 50s and a man in his 60s, in Royal Adelaide Hospital in a stable condition.

Australian Associated Press