The entire state is now locked down and a police blitz is underway to enforce tough new regulations and increased fines as authorities battle to contain the spread of the Delta strain of the virus.

"We urge everyone in (the western and south west Sydney) to appreciate that every day they set foot out of their house, they should assume they're going to come into contact with somebody who has the virus," said Premier Gladys Berejiklian.

"And that is a fact, it's not just an assumption."

Nearly 80 per cent of the new cases were recorded in 12 local government areas of concern, which face new, tougher restrictions announced on Friday.

The three deaths include a man in his 90s and a man in his 80s who were residents at Greenwood Aged Care at Normanhurst, where an unvaccinated staffer worked two days while infectious.

Six residents at the aged care facility have now tested positive, of whom four are not vaccinated as they declined to be immunised, said Deputy Chief Medical Officer Marianne Gale.

The third death is a woman in her 90s from south west Sydney who died at Liverpool Hospital. She caught the infection in the hospital's geriatric ward, taking the number of deaths connected to that outbreak to ten.

A party in Maroubra, attended by up to 60 people, has led to 16 positive cases.

NSW Health Minister Brad Hazzard condemned the revellers, and also criticised hundreds of people who attended a funeral in western NSW.

"Many of those people are now returned to the far flung parts of our state and I'm already hearing from our health system that there are cases that are positive in various communities and those will probably grow in the next few days," Mr Hazzard said.

"There is no time now to be selfish."

Meanwhile, trains are skipping major Sydney train stations, taxis and Ubers are banned from city zones, and traffic is slowing to a crawl as police fend off a planned anti-lockdown protest.

NSW Police have been warning Sydney residents not to show up to the protest planned to start in the inner city on Saturday afternoon.

More than 1500 officers will be stationed around the CBD, and a police chopper began circling above the protest's planned starting point from around 10am.

Taxi and rideshare services are again shut out of the city between 9am and 3pm, with companies facing fines of up to half a million dollars if they take passengers to central Sydney.

The lockout zone extends from Lilyfield to Zetland to Milsons Point, and eastwards to Edgecliff - an area much larger than just the CBD.

Trains won't be stopping at Redfern, Town Hall, Martin Place, Wynyard, Circular Quay, St James and Museum before 2pm.

Police have reduced ten major roads - including Oxford St in Paddington, Parramatta Rd at Annandale and the Pacific Highway at St Leonards - to a single lane for their operation.

The alleged organiser of the protest will spend at least three months in jail for failing to comply with NSW public health orders.

The persistently high numbers have led Premier Gladys Berejiklian to prolong stay-at-home orders in Sydney until at least September 30 and impose harsher rules on a dozen hotspot local government areas, including a curfew from 9pm to 5am.

From Monday, mask-wearing will be mandatory for all people in NSW when outdoors, except when exercising.

Construction sites will also face a compliance blitz as SafeWork NSW officers hunt for rule-breakers this weekend.

Three Sydney building sites saw fines of thousands of dollars each in the last week for not ensuring their workers were vaccinated.

One site in Liverpool has to cough up $20,000 after inspectors found its workers were not wearing masks or scanning QR codes, and their boss hadn't ensured they were vaccinated or tested.

Australian Associated Press