Australia reported eight new locally acquired Covid-19 cases in Queensland on Tuesday (March 30) and authorities warned more could emerge as the state scrambles to quash an outbreak linked to the highly contagious United Kingdom variant of the coronavirus.

Two returned travellers from Papua New Guinea have also tested positive in hotel quarantine in the past 24 hours.

Premier Annastacia Palaszczuk says six new cases are genomically linked to or close contacts of seven existing infections, while the other two are under investigation.

Two of them are under investigation.

'We just have to take this day by day, ' Ms Palaszczuk said. So, we have six linked locally acquired cases, which is good - they're all linked.

"Do we expect to see more cases - probably, probably we will see more".

One person linked to the pair, and another five people who attended a party with them in Byron Bay, also tested positive in Brisbane and the Gold Coast overnight.

"Everyone is anxious", she said.

"We know these lockdowns work, they obviously affect travel, business, holidays and health, they're not ideal but they work", Dr Faint said.

"All of our cases are linked to either the first cluster with that doctor who worked at the PA or this second cluster, which is a brand new cluster unrelated to that first cluster linked to the nurse", Dr Young said.

The first cluster is genomically linked to a PA Hospital doctor who tested positive on March 12.

A Queensland nurse and her sister unknowingly infected with the virus were in Byron for a weekend-long hens party, visiting a number of locations including the busy Beach Hotel.

Dr Young said she would mandate that anyone working with COVID-19 patients has to have had their first vaccine dose.

"Anyone, anywhere in Queensland. with any symptoms please come forward, that is critical", she said.

He said people should avoid doing out into the community where possible.

Ms Palaszczuk revealed a new mandate for the vaccination of frontline health workers.

"It stands to reason that maybe if these staff had been vaccinated (or) not been treating COVID-positive cases, then we might not be in a lockdown", shadow health minister Ros Bates said.

The Queensland Leader said given they were dealing with the highly-contagious United Kingdom strain of COVID-19, more cases were likely.

She is expected to hold a media conference at 9am. Probably we will see more.

'I can't predict what's going to happen in the next week or two'.

Both clusters are the highly infectious United Kingdom strain and have sparked a three-day lockdown of the Greater Brisbane area that is due to end on Thursday evening. And we needed to do it quickly.

"My understanding is that over the next couple of weeks there will be 100 per cent of people vaccinated, and around 7000 people have been getting their second vaccinations", she said. "But, of course, we want to make sure that that particular cohort gets their vaccine as soon as possible".

"So, close contacts of both of those clusters".

Nurse cluster The nurse cluster spread at a hen's party in Byron Bay.