South Australia will extend its travel ban on Victorians to cover the entire state in response to the latest COVID-19 outbreak in Melbourne.
SA had previously banned travellers just from Greater Melbourne.
Chief Public Health Officer Nicola Spurrier said the decision to extend the travel ban would better support the lockdown measures put in place in Victoria.
"We understand this will have an impact on people but it is supporting the requirement Victoria has imposed on its citizens," Professor Spurrier said.
The only exceptions to the new provisions will be Victorians who reside within 70 kilometres of the border, who will be able to come and go as usual.
Professor Spurrier said the increased restrictions also reflected the limited testing being conducted in some regional centres, as Victorian authorities concentrated on the areas of most concern in Melbourne and Bendigo.
The Victorian coronavirus cluster has now grown to 30 cases.
Police Commissioner Grant Stevens said further to the border closure, anyone who had travelled into SA from regional Victoria since May 26 would be required to get tested immediately and isolate until they receive a negative result.
They must also get tested on days five and 13 and are banned from attending large events covered by COVID management plans, including any AFL games.
Mr Stevens said it was unclear how long the border closures would be in place.
"We can't put an end date on it at this point in time. We are watching very closely what is happening in Victoria," he said.
"We will monitor it on a daily basis and make changes when we can."
SA reported no new coronavirus infections on Friday and has just two active cases, both returned travellers in hotel quarantine.
Chief Public Health Officer Nicola Spurrier said SA Health has sent out about 50,000 SMS messages to people who may have been in Victoria in recent weeks, with responses received from about 21,000 of those.
The rest were urged to complete the requested survey as soon as possible.
Contact tracers have also been in touch with about 320 people considered close contacts of a Victorian case, including those who attended an AFL match in Melbourne last weekend.
Those people are now in quarantine at home.
SA conducted more than 8000 virus tests in the past 24 hours and has moved to increase resources, including operating one major centre in Adelaide around the clock.
Australian Associated Press