WA authorities on Saturday moved to reclassify South Australia from a “very low risk” to a “low risk” jurisdiction, meaning all SA arrivals in WA will have to self-quarantine for 14 days.

South Australia has recorded eight interstate acquired COVID-19 cases since opening its borders to the eastern states on November 23, although authorities are yet to detect any instance of community transmission.

WA Premier Mark McGowan said the move to shut the border was a “high precautionary measure”, citing the threat of the new Omicron variant.

“WA’s chief health officer advises the risk of transmission from South Australia into Western Australia is increasing,” he told reporters.

“Lots of people are coming in with cases into South Australia who are then being managed in a home quarantine arrangement.

“The prospect is the omicron variant could get into Adelaide and South Australia.

“It’s a highly precautionary measure, I realise it will be disruptive, it will be inconvenient for some families, but I’ve got to take account of the greater good here.”

South Australian Premier Steven Marshall labelled WA’s decision a “massive inconvenience” for WA travellers in SA.

The South Australian premier was involved in a similar row with McGowan in December last year, when WA’s border remained shut to South Australian arrivals over the holiday season.

“[It’s] a massive inconvenience for people from Western Australia who got told at a moment’s notice that when they go back to Western Australia, they’ll need to do 14 days of quarantine,” he told reporters on Sunday.

“Obviously, [it’s] hugely impactful for people who are looking to go to Western Australia, we still haven’t had community transmission in South Australia but Western Australia are being very very careful, but very very inconvenient for many people who were planning to travel there.

“I know there’ll be so many people that are disappointed with this decision … because they were hoping to reunite family and friends over the Christmas period, that’s now not going to be possible.”

Marshall later said, “we are concerned what Queensland, what the Northern Territory and what Tasmania might do” in response to South Australia opening to the eastern states.

SA Health over the weekend changed testing requirements for travellers from NSW, Victoria and the ACT, requiring them to show proof of a negative COVID test 72 hours before boarding a flight to SA.

Previously, travellers from the eastern states were only required to be tested on arrival.

“What we really noticed was that with some of new infections coming in, some of them were highly infectious, which meant we had to put an entire plane into quarantine, and this was hugely inconvenient,” Marshall said.

“So we’re now asking people to have that test and have a negative test before they get on board.”

South Australia recorded no new cases of COVID-19 on Sunday – the first zero case since the state opened its borders on Tuesday.

-with AAP