South Australia is once again tightening its border controls with Victoria, prohibiting anyone from entering the state from midnight on Tuesday, including South Australians.
South Australians are officially allowed back home but have to quarantine for two weeks and undergo two compulsory coronavirus tests.
The most essential travellers will still be allowed some exemptions.
People will continue to be able to enter South Australia from other states, but those who enter from NSW and the ACT will also have to quarantine and undergo mandatory checks.
South Australia also reinstalls caps on big crowds.
A limit of 100 people will be held at funerals and weddings from midnight on Tuesday, and home gatherings will be capped at up to 50 guests.
“Our primary focus is keeping everyone in South Australia safe and secure,” Mr Marshall said.