Lismore and Albury are going back into lockdown just days after restrictions lifted, with COVID-19 cases detected in the regional NSW towns.
Some 1351 new locally-acquired cases were recorded in the 24-hours to 8pm on Wednesday across the state, as well as 12 deaths, which takes the toll for the current outbreak to 210.
Dozens of new cases were diagnosed in regional NSW, including one in Lismore, near the Queensland border, and two in Albury, on the Victorian border.
Stay-at-home orders will resume in both towns from 6pm on Thursday for at least seven days.
The sources of the infections in Albury are unknown, Deputy Chief Health Officer Dr Marianne Gale said, but they are possibly linked to Sydney.
"Those people appear unrelated to each other (and) there are a number of exposure sites," she said.
"So I'd ask everybody living in the Albury area to please be vigilant for systems and come forward for testing."
The Lismore case is also possibly linked to Sydney, with potential exposure sites including a school.
The case has prompted a change in the "border bubble" arrangement negotiated only days ago after weeks of sparring between the Queensland and NSW governments, with the city of Lismore declared a restricted zone again.
Anyone who has been in the area in the past 14 days will now be unable to enter Queensland, the same as the majority of NSW residents.
A case has also been identified in Glen Innes, inland from Coffs Harbour, since the 8pm cut off, with a lockdown of that area also likely.
New cases in western NSW spiked to 27, after recording six the previous day, taking the total number of cases there past 1000.
"We're still seeing a significant number that aren't linked, and people infectious in their communities, and so it would be very premature for us to think that we've got in front of this current outbreak," Local Health district CEO Scott McLachlan said.
Some 59 cases were also detected in the Nepean Blue Mountains, 44 in the Illawarra, 23 on the Central Coast, 16 in the Hunter New England, three in southern NSW and two in the state's far west.
One case was also recorded in northern NSW, the Lismore case.
It comes as lockdown lifts for an additional 12 regions from 1pm on Thursday.
Those areas are Bega Valley, Blayney, Bogan, Cabonne, Dungog, Forbes, Muswellbrook, Narrabri, Parkes, Singleton, Snowy Monaro and the Upper Hunter shire local government areas.
However Forbes could soon also find itself back in lockdown, after the fragments that cause COVID-19 were detected in the town's wastewater.
With schools breaking up for two weeks from Friday, Mr Barilaro urged families in the regions to avoid travel.
"The reality is it's not these school holidays you should travel," he said.
"I encourage people to stay home and only travel if they need to and to avoid areas that are under lockdown conditions.
"Stay home and spend that time with family because it's a freedom you have."
Australian Associated Press
Sign up for our newsletter to stay up to date.