Another eight coronavirus cases have emerged in Queensland, with two clusters now totalling 15 cases, triggering concerns that Greater Brisbane's lockdown may be expanded and extended.
Premier Annastacia Palaszczuk says six new cases are genomically linked to or close contacts of seven existing cases, while the other two under investigation.
She says there are now two distinct clusters of the UK variant of COVID-19 in Greater Brisbane, which has been locked down for three-days to stem the spread.
"Now of course we want to get on top of this community transmission," Ms Palaszczuk told reporters.
"So the steps that we took to go into this lockdown, as you can see by those numbers of community transmission today, were absolutely the right call."
There are now more than 60 potential virus exposure sites across Greater Brisbane, the Gold Coast and central Queensland.
About 2.5 million people in Greater Brisbane were ordered into a snap three-day lockdown on Monday afternoon.
Hundreds more people around the state who have visited Brisbane since March 20 are also under orders to stay at home and self-isolate.
The premier raised the prospect that the lockdown could be extended past 5pm on Thursday.
"We just have to take this day by day, " Ms Palaszczuk said.
"I said that we will give you the most up to date information we can every single morning, and so far the fact that we have these cases that are linked is good news, that is good news.
"Do we expect to see more cases - probably, probably we will see more.
"The big question will be whether or not we see unlinked community transmission."
One known case lives on the Gold Coast and others have visited Toowoomba, Gladstone, Hervey Bay and Gin Gin while infectious.
Chief Health Officer Jeannette Young has also left open the door to expand the lockdown to other regions.
She said it would depend on the number of virus cases that turn up.
"The message here is that people should be on alert, no matter where they are in Queensland," Dr Young said.
She said both clusters are either genomically linked to, or close contacts of, two Princess Alexandra Hospital staff who tested positive.
The first cluster is genomically linked to a PA Hospital doctor who tested positive on March 12.
The cases linked to the doctor include two men in northern Brisbane, the brother of one of the men and two colleagues of the other man.
The second cluster are close contacts of a PA Hospital nurse and her sister.
A close contact, and another five people who went to a hen's party with the pair in Byron Bay, tested positive in Brisbane and the Gold Coast overnight.
Dr Young said another two cases are believed to be linked to the first cluster, but genomic testing is underway.
"We know they're in close contact - you're getting this information, almost at the same time I get the information, which is why I apologise I don't have all the answers," she told reporters.
Dr Young has also mandated that healthcare workers must have received their first vaccine dose to be able to treat COVID-19 patients.
More than 41,000 frontline workers have received their first jab already, but only about 7000 are fully vaccinated.
