South Australia has closed its border with NSW because of the rising number of COVID-19 cases in Sydney.
Premier Steven Marshall says the situation in NSW is deteriorating and immediate action has been taken to keep South Australians safe.
The ban will not apply to essential workers, returning South Australians and other people granted exemptions.
There will also a 100-kilometre buffer zone along the border to allow people living in close communities, including Broken Hill, to still travel into SA.
"It's unfortunate that this has to be done. We do recognise this causes a significant impact on people," Police Commissioner Grant Stevens said.
"Clearly, the advice from SA Health has created an elevated level of concern."
Mr Stevens said people already in transit to SA, by air or road, would be managed at the airport and on the border and either granted exemptions or turned around, depending on their individual circumstances.
People allowed to stay may be still required to quarantine for 14 days.
The border closure follows more reported virus cases in Sydney on Wednesday, taking the current outbreak to 31.
