South Australia will enforce border restrictions with NSW and Victoria until officials are absolutely sure both states "have got their act together" on the movement of people from COVID-19 hotspots, Premier Steven Marshall says.
SA on Friday maintained its requirements for people from the two states and the ACT to quarantine on arrival in SA in response to the surge in coronavirus cases in Melbourne.
Mr Marshall says he's pleased with the way the ACT and NSW are travelling in suppressing the virus, but health officials continue to monitor the movement of people between NSW and Victoria.
"We are moving as a nation towards the management of hotspots," the premier said.
"But this is a new arrangement so what we need to be 100 per cent sure about is that Victoria and NSW have got their act together, making sure that people from hotspots do not leave their home state.
"We don't want to keep (restrictions) in place any longer than we need to.
"But the transition committee formed the opinion that there was still a bit more work to do."
SA will next consider the issue of borders at a meeting of the transition committee on Tuesday.
It had planned to lift the isolation measures on July 20, but recently abandoned that timeline after the issues in Melbourne.
It has already lifted restrictions for travellers from Western Australia, Tasmania, Queensland and the Northern Territory.
Police also revealed on Friday that two men had twice been caught crossing into South Australia from Victoria in breach of the border restrictions, the second time after their car became bogged on a dirt road.
It was further confirmed a security guard monitoring returned travellers quarantined in an Adelaide hotel had been taken off the job for breaching safety protocols.
SA Chief Public Health Officer Nicola Spurrier said the guard wasn't wearing a mask and was dismissed by police.
"It didn't put anybody at risk, but it was just a warning: 'OK, you've been told you have to wear a mask. You're not wearing it. You're out of here'," she told ABC radio on Friday.
No new virus cases were reported in SA on Friday with the state's three remaining active infections being repatriated Australians who arrived in Adelaide last weekend.
They are among about 350 people still in quarantine at a city hotel, including about 100 defence force personnel.
Australian Associated Press