On Friday, there were 516 new infections reported as NSW Health revealed three people who tested positive to Omicron the previous day had attended the Flow Fridays – 90s Themed Boat Party on December 3.
It has created concern it could be the next super spreader event.
Already five people who attended the event have tested positive to the virus and NSW Health said they expected more Omicron cases to present.
More than 100 have now been forced into isolation.
NSW Health said it was concerned about the "increased transmission taking place in larger social venues" such as pubs, clubs and party settings.
"This includes recent outbreaks associated with the Golden Sheaf Hotel at Double Bay, the Oxford Tavern at Petersham and the Albion Hotel at Parramatta," a statement said.
"The transmission in these types of settings is contributing to the increase in cases in NSW and we urge people not to attend social functions if they have any symptoms, even if mild."
Victoria records 1193 new Covid cases, 13 deaths
Victoria has recorded 1193 new Covid-19 cases and 13 deaths on Saturday.
That brings the total number of active infections in the state to 11,457.
There are currently 323 people hospitalised, 68 of whom are in ICU. Of those, 29 are on ventilators.
There were 82,895 tests conducted on Friday.
The state's vaccination rate has increased to about 92 per cent, with 4056 doses administers yesterday at state-run clinics.
On Friday, 1206 infections were reported, and two deaths.
Victoria recorded its first case of the new Omicron variant on Wednesday.
There are now three confirmed cases of the variant in Victoria, but Premier Daniel Andrews said authorities were not chasing "an Omicron zero strategy".
That was because it wasn't the "smart thing to do" and wasn't achievable.
"We'll be guided by the growing body of international evidence about the transmissibility and infectivity of this new variant but also the relatively positive signs that the disease is milder and certainly not more severe than the Delta variant," Andrews said.
