Additional military troops are likely to be called into virus-hit areas of NSW and may be used to help administer AstraZeneca vaccines.

NSW reported 345 new local COVID-19 cases in the 24 hours to 8pm on Wednesday. At least 91 were in the community while infectious, while 138 remain under investigation.

Two Sydney men in their 90s have also died, including one resident of Wyoming Aged Care in Summer Hill. One of the men had received one vaccination dose while the other was fully vaccinated.

"We can understand people in their 90s are frail and vulnerable," Deputy Chief Health Officer Marianne Gale told reporters on Thursday.

More than six million people in Greater Sydney and surrounds are in lockdown at least until August 28 as authorities battle to contain the virulent Delta strain outbreak.

Northwest NSW, Dubbo, Armidale, Tamworth, Byron Bay and the Hunter region are also enduring snap lockdowns.

However, Health Minister Brad Hazzard says the government has no intention of implementing a statewide lockdown, despite a surge of COVID-19 cases leaking out of Sydney.

He admitted health systems in rural areas - particularly in northwest NSW, home to large Indigenous populations - were stretched.

"There is a defining difference between NSW and other states - we have always tried to keep as much of NSW open as possible," he said.

"We will progressively look at those areas that have problems but at this stage I don't see any reason on the advice I've had to date why we would move further than (where) the problems are."

Premier Gladys Berejiklian said from Thursday the local government areas of Bayside, Strathfield and Burwood would face restrictions akin to those in west and southwest Sydney.

There are now 12 council areas under the harsher restrictions, incorporating more than 50 per cent of Greater Sydney residents.

These people are unable to leave their council areas unless authorised workers and must shop and exercise within 5km of home.

Ms Berejiklian also flagged tougher lockdown compliance measures, anticipating more military assistance in the coming days.

NSW Police Commissioner Mick Fuller was working with health officials on a range of measures to let the government know "what he needs to clamp down on compliance", she said.

Mr Fuller will report back to the government by week's end.

The premier and NSW Health's Dr Gale both reiterated that all adults in Greater Sydney should urgently seek out any available vaccine.

"People are realising, you might think you are OK with the virus but your closest loved ones will not be," Ms Berejiklian said.

Meanwhile, NSW Health says workers at Sydney Markets in Homebush have access to COVID-19 vaccinations this week, at overnight pop-up clinics set up on site.

The AstraZeneca clinics started on Wednesday night, running from 10.30pm to 5.30am, and will open again overnight on Thursday.

To make it easier for delivery drivers and stall operators to get vaccinated, day clinics will also open on Friday and Saturday for workers.

More than 6400 supermarket and food industry workers have so far been vaccinated at the NSW Health Vaccination Centre at Sydney Olympic Park.

There are 62 COVID-19 patients in intensive care, with 29 ventilated.

Australian Associated Press