The Delta outbreak, which began in Sydney's eastern suburbs 54 days ago, has been concentrated around Fairfield, in the city's south-west, for several weeks.
But 92 of 319 new cases recorded in the 24 hours to 8:00pm Friday were from the Canterbury-Bankstown local government area (LGA), sparking warnings the virus was on the move again.
NSW Health Minister Brad Hazzard said there had been "a rapid increase" in COVID infections in the LGA this week, with around 500 new cases identified.
Authorities are concerned about compliance in the area, and NSW Police Deputy Commissioner Gary Worboys warned officers would increase patrols over the weekend.
He claimed some people were congregating in shops — something banned under Greater Sydney's strict stay-at-home orders, which stipulate only one person from a household may leave home once a day to buy essential items.
Deputy Commissioner Worboys singled out the suburb of Campsie as a particular problem area.
"People are going out together, whether that is a butcher shop, a fruit and vegetable shop or whether that is going to a supermarket or another small store and are using that to then gather and congregate, and clearly that is an area of risk that we really want people to appreciate that that is where the virus will spread," he said.
Canterbury-Bankstown is NSW's most populous LGA, home to 370,000 people.
Its mayor, Khal Asfour, said most people in the area were doing the right thing.
"They need to be careful with their messaging," he said.
"We shouldn't be targeted as the epicentre when we're a large council area and the majority of people are doing the right thing.
"We're tired of being singled out."
A NSW Police spokesperson said 335 penalty infringement notices were issued on Friday to people around the state who had breached the COVID-19 public health orders.
They could not say how many of those were in Canterbury-Bankstown.
Mr Asfour said there was a range of factors driving the increase of COVID-19 cases in his area, including the fact there were "a lot of authorised workers that live in our LGA that cannot work from home".
"They're out in the community, they're out servicing Greater Sydney in different industries and they might be bringing the virus back with them."
Mr Hazzard put the spotlight on small businesses in the area, claiming many were not doing the right thing.
Earlier this week, at least a dozen staff at a KFC store in Punchbowl, which is in the central part of the LGA, contracted COVID.
"That just shouldn't be happening," Mr Hazzard said.
"If you comply with your COVID-safe plan, everybody wears a mask, they socially distance, they don't hang out in the tea room afterwards, they don't hang out chatting, then people won't get it."
Anyone who visited the fast-food outlet from July 27 to August 2 has been deemed a close contact.
"You need to have a COVID-safe plan and stick to it because you don't want your business to be the one that gets shut down," Mr Hazzard said.
"But you also don't want to see all of your staff positive."