SA's transition committee met on Thursday and resolved to apply level three measures to people from Victoria's western local government areas.

That requires them to get tested on days one, five and 13, and isolate until they get their first negative result.

The change was to apply from midnight on Thursday but stalled when Victorian Premier Daniel Andrews announced another week-long lockdown.

"Changes announced following the state's transition committee this morning have been put on hold following the announcement that Victoria will go into lockdown for seven days at 8pm tonight," SA Police Commissioner Grant Stevens said.

"This is an evolving situation and will continue to be monitored."

SA had already decided against changes to border rules with Queensland.

At present people from the state's southeast and Brisbane cannot enter or return without an exemption while South Australians in regional Queensland can return provided they get tested.

But it has eased some local restrictions including moving to a general density requirement of one person to every two square metres, allowing most venues - including pubs and restaurants - to operate at 50 per cent capacity.

Sports competition can resume with spectator numbers at outdoor venues limited to 1000 - but SA will keep mask-wearing in place for high-risk settings, high schools and most public places, including shopping centres.

Family gatherings will continue to be limited to 10 people, and weddings and funerals will remain at 50.

All food and drink consumption must be seated.

A crowd of 15,000 has also been approved for the AFL game at Adelaide Oval between Port Adelaide and the Adelaide Crows this weekend.

Bans on singing and dancing remain but are likely to be the next reviewed by officials.

Premier Steven Marshall said the state government did not want to keep any restrictions in place for one day longer than necessary.

"But the advice is pretty clear at the moment, we are still in the danger zone," he said.

"We can see unfolding situation interstate so we are taking a prudent approach."

SA reported no new cases on Thursday but still has 20 active infections.

Most of those are linked to the Modbury cluster which forced the state into a week-long lockdown last month.

The cluster was sparked by an 81-year-old man who had recently returned to Australia from Argentina and had quarantined in Sydney before travelling to Adelaide.

Genomic testing confirmed he contracted the disease in Sydney but the precise source remains unknown.

Australian Associated Press