Five new cases of community transmission have been detected in Sydney, all of which are linked to the existing Avalon cluster, New South Wales (NSW) Premier Gladys Berejiklian announced on Monday.
The cluster, concentrated in Sydney's Northern Beaches, now consists of 125 cases.
Restrictions remain relatively unchanged - however, residents of the Northern Beaches have been offered some respite for New Year's Eve, with authorities allowing households in the northern zone to have a maximum of five guests - also from the northern zone - in their homes for December 31 only. This also applies for outdoor gatherings.
Those in the southern zone of the Northern Beaches will be allowed to host 10 people in their homes, provided the guests are from the same zone.
Speaking to reporters, Berejiklian said overall restrictions would not be eased. On New Years Eve, no crowds are permitted on Sydney's foreshores "whatsoever" to watch the fireworks display.
"There are still too many concerning aspects of those cases - and not being able to identify the unlinked cases - for us to really ease restrictions," she said.
"My strong message to everyone in Greater Sydney this year is to watch the fireworks on TV."
For those in the northern zone of the Northern Beaches - north of the Narrabeen Bridge and east of the Baha’i temple - stay-at-home provisions will remain in place until January 9 due to the large number of active cases.
Restaurants in Sydney's CBD are permitted to host guests with a booking - and a permit through Service NSW - as long as the four-square-metre social distancing rule and safety measures are abided.
Greater Sydney residents are permitted to have 10 people in their homes and are able to attend a venue in the CBD - with a booking and a permit - on New Year's Eve.
Those living in the CBD are also permitted to have a maximum of 10 people in their homes, but are required to log their guests on the Service NSW website.
Unless people have a permit, "nobody should be in the CBD at all" on New Years Eve, Berejiklian said.
"You can't just jump on a bus or the train and come into the CBD on New Year's Eve."
Outdoor gatherings in Greater Sydney will be reduced from a maximum of 100 people to 50, the Premier announced. Social distancing must be adhered to and groups of 50 should not "converge" with others, she said.
No changes have been made to the restrictions for regional NSW.
Council events are permitted to continue on Friday night, but they must be controlled and seated with no mingling, and record-keeping requirements must be strictly adhered to.
A short, seven-minute fireworks display will continue as planned at midnight.
The origin of the Avalon cluster remains unknown.