The Queensland-NSW border will remain open despite Brisbane heading into lockdown, but returned travellers from affected areas in Queensland will be required to isolate in NSW.
Brisbane, Ipswich, Logan, Moreton Bay and Redlands council areas in Queensland will be placed into lockdown from 6pm Friday until 6pm Monday. They will only be able to leave their home for essential reasons and will have to wear a mask outside the home. The lockdown comes after a hotel quarantine cleaner contracted the mutant UK strain of COVID-19.
Any people who have returned to NSW from affected Queensland areas since January 2 will be held to the same lockdown rules as Brisbane and will be asked to stay home and only leave for essential reasons.
"I'm sure today there will be people calling on NSW to close its border to Queensland," acting NSW Premier John Barilaro said.
"At no point during this pandemic have we had a knee jerk reaction or treated the border like a light switch."
It comes as four new cases were detected in NSW in the 24 hours to 8pm on Thursday with a further seven found in hotel quarantine. There were from 26,112 tests conducted in the 24-hour period.
Two of the cases were linked to the Berala cluster, a woman in her 50s and a teenage boy, while a third was a close contact of the Croydon cluster. All three were in isolation for their infectious periods.
The fourth has been linked to the Avalon cluster, a man in his 40s who tested positive several days after completing his 14 day isolation. He had tested negative three times during his isolation period and his case remains under investigation.
Despite the new case, NSW Health Minister Brad Hazzard announced that restrictions on the Northern Beaches will be relaxed from Sunday. Mr Hazzard said with "confidence and some reservations" the Northern Beaches will be counted as part of Greater Sydney from 12.01am on Sunday.
A-League matches - including the Newcastle Jets clash with Western Sydney in Newcastle on Friday night - will be under the same public health order as the Sydney test cricket match for the rest of January, meaning all attendees will be required to wear masks.
Alerts have also been issued for three new Sydney locations - Chemsave at Wentworthville and both Chemist Warehouse and Woolworths at Avalon - that were visited by infected cases.
A positive sewerage detection was also found in a treatment plant in Ulladulla. Chief Health Officer Dr Kerry Chant said the result may have been from a traveller passing through the area, but that local residents should remain on high alert.