NSW Premier Gladys Berejiklian says schools in the state will remain open, but has encouraged parents to keep their children at home to contain the spread of coronavirus.

Key points: At 8:00pm yesterday, there were 669 confirmed coronavirus infections in NSW

At 8:00pm yesterday, there were 669 confirmed coronavirus infections in NSW Victorian Premier Daniel Andrews has announced schools in his state will close

Victorian Premier Daniel Andrews has announced schools in his state will close However, in NSW they will remain open

It comes as health authorities announced almost 50 people who travelled on the cruise ship at the centre of a coronavirus outbreak in Sydney have returned positive COVID-19 tests.

The cruise ship Ruby Princess docked in Sydney last week, when thousands of passengers were allowed to disembark, despite 13 people on board having been tested for coronavirus.

Ms Berejiklian said the decision to keep schools open would ensure parents with limited childcare options could continue working.

The Premier said last week, before any restrictions were announced, about one third of parents had already decided to keep their children home from school.

At 8.00pm on Sunday there were 669 confirmed cases of coronavirus in NSW — an increase of 136 in 24 hours.

All schools in NSW will provide online learning options for the remaining three weeks of term one.

It remains unclear what will happen after the school holidays. Classes are due to resume on April 27.

The Premier said no child would be turned away from a NSW public school during the health crisis.

"For parents that have no option, for parents that are workers, school is safe for children to attend and schools will remain open," she said.

NSW Education Minister Sarah Mitchell said teachers with health conditions that could make them high-risk coronavirus patients would be allowed to work from home, and deliver lessons online.

"In challenging times we think this is the right decision to make," she said.

Yesterday Victorian Premier Daniel Andrews announced schools in his state would shut from Tuesday but Ms Berejiklain said it was more practical to keep them open in NSW.

Cruise passengers test positive

Meanwhile, after it was revealed last week that passengers on board the Ruby Princess had tested positive for coronavirus, the NSW and Federal governments traded barbs about the way the ship's arrival was handled.

NSW Health said 48 passengers on the boat had now returned positive tests for COVID-19.

Of those, 27 are in NSW and 21 are interstate.

In the 24 hours to 8:00pm Sunday, 136 more coronavirus cases were recorded in NSW.

The state's chief medical officer Dr Kerry Chant said the latest increase in coronavirus cases was the highest to date over a 24-hour period, and that there were now 10 people being treated in intensive care units.

She urged people to take social distancing seriously.

"I'd particularly like to urge young adults ... it is incredibly important that you play your role in the social-distancing measures to protect the most vulnerable at this time," she said.

Ms Berejiklian said people should stay home.

"Your personal actions can result in someone getting very sick or dying," she said.

Gladys Berejiklian and the secretary of the NSW Department of Premier and Cabinet Tim Reardon in last night's meeting. ( Supplied )

The Prime Minister yesterday announced a sweeping shutdown of non-essential services in Australia after a national cabinet meeting and public pressure from NSW and Victoria.

Mr Morrison slammed people who crammed onto beaches and into pubs and clubs at the weekend, and said it forced the nation's leaders to impose harsher rules.

"When we all do not do the right thing, then it has real implications for others," he said.

Ms Berejiklian said she was "relieved" the measures proposed by her Government were adopted by the cabinet.

"The buck stops with me," she said.

"[And] this is a no regrets policy. I don't want to look back in a month and think 'why didn't we do that?' 'Why couldn't we save more lives?' I don't want those regrets."

From midday Monday, these businesses will be closed:

pubs

pubs clubs

clubs cinemas

cinemas casinos

casinos nightclubs

nightclubs indoor places of worship

indoor places of worship gyms

gyms indoor sporting venues

Several beaches in Sydney have already closed, as have many public pools and libraries.

Supermarkets will stay open, as will petrol stations, pharmacies, banks, hairdressers, beauticians, bottle shops and convenience stores.

Public transport is considered essential, but services could be decreased.

The ABC will also continue broadcasts.

Cafes and restaurants will still be able to serve takeaway food and beverages.