Health authorities in NSW have confirmed five new locally acquired COVID-19 cases, which are all are linked to known sources.

Five infections among returned travellers in hotel quarantine were also recorded in the 24 hours to 8pm Thursday.

Four of the new local cases have been linked to a private health clinic cluster, with three being household contacts of a case reported on Thursday and one a co-worker from another clinic of the same provider.

NSW Health said the fifth new local infection was most likely an old case acquired in August and can be linked to the Liverpool Hospital cluster.

There were 12,868 people tested across the state on Thursday.

NSW Premier Gladys Berejiklian said she was still looking at what social distancing restrictions could be eased in her state, despite a resurgence in locally acquired infections this week.

“The advice we get from health is always evolving depending on where we are in the pandemic,” she said.

“I’m always concerned when we have new cases of community transmission, [but] it shouldn’t preclude us looking at what opportunities we have in the next few weeks.”

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Ms Berejiklian said her government was getting advice from health experts and economists.

“We haven’t ruled out any further easing of restrictions,” she said.

“We are considering what will happen in the next few days and beyond.”

Health authorities also found a new infection on board a ship that travelled from Brisbane to Newcastle with international mariners onboard this week.

Chief health officer Kerry Chant said 14 crew members were swabbed yesterday and one tested positive for COVID-19.

“It was initially thought that that test result was reflecting an old infection but further testing has had to be under way because the test results are still inconclusive,” she said.

Dr Chant said the boat did not pose a risk to the community and would remain docked in Newcastle while further testing was completed.