Sydneysiders face dramatically tightened virus restrictions within hours, including restrictions on travel, after community cases spiked again on Wednesday.

The cluster that began in Sydney’s east hit 31 cases on Wednesday, with more than a dozen more infections added to the tally.

They included 10 locally acquired infections reported by 8pm Tuesday (seven of which had already been announced) and a further 13 that will be part of Thursday’s numbers.

Health Minister Brad Hazzard said Sydney was in a serious situation, with the outbreak of the virulent Delta strain spreading across the metropolitan area.

“We have gone from that near and present danger to a very real and present danger, not just in a shopping centre but right across Sydney,” he said.

“I am as worried now as I have been any time since January last year, so we need to make sure that we are all looking after each other.”

Premier Gladys Berejiklian said the new restrictions would be “effective immediately” where possible. Officially, Sydneysiders will have until 4pm Wednesday (AEST) to comply.

“Please abandon non-essential activities, please don’t attend social gatherings unless you absolutely must,” Ms Berejiklian said.

The new rules for greater Sydney, the Blue Mountains, Shellharbour and the central coast include:

• No more than five visitors to any household, including children;
• No standing up to dine or drink in hospitality venues, no mingling;
• No singing or dancing at any venue (except weddings, where 20 people will be allowed on a dance floor at a time);
• Indoor venues revert to a cap of one person per four square metres;
• Stadiums recommended to follow a cap of 50 per cent capacity; masks mandatory;
• Masks mandatory in all indoor settings, including workplaces;
• Gym classes limited to 20, with masks mandatory;
• Public transport returns to capacity guided by “green dots”;
• Those who live or work in the seven local government areas that are the focus of the spread must not travel outside metropolitan Sydney unless visiting a relative or for essential work.

The seven affected council areas are: Sydney city, Woollahra, Bayside, Canada Bay, Randwick, Inner-West and Waverley Council.

“These are measures we have to take now so we don’t have to do anything more severe down the track,” Premier Gladys Berejiklian said.

“But we are putting them in place now in a bid to prevent us having to take further action.”

Ms Berejiklian refused to rule out further action – but again stopped short of imposing a snap lockdown.

“I am not going rule out what happens beyond a week, because we don’t know. We certainly didn’t expect this situation a few days ago,” she said.

“Responding to a pandemic means you look at the facts, you look at the response, you look at where spread is or isn’t occurred in and you are accordingly.

“We have had the response in NSW not to burden our citizens unless we absolutely have to do.”

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Chief health officer Kerry Chant said authorities remained concerned about unlinked cases – including a nine-year-old girl from a Waverley primary school and a man in his 30s who attended a party in West Hoxton, on Sydney’s south-western fringe, that is linked to nine other positive tests.

“The cause of our concern is that we have had people infectious in in the community unknowingly,” she said.

NSW authorities are focusing on a broad swathe of Sydney’s south and the CBD and its surrounds as they chase down transmission of the virus.

That follows confirmation of an infection in a child at a daycare 60 kilometres south-west of Sydney. Dr Chant said that case was believed to be linked to the West Hoxton birthday party, which was last Saturday night.

“The person attending the party was not symptomatic, had no indication, promptly went for testing. We got to this group very quickly,” she said.

“That meant that they were basically infectious in the community for one day, probably … Unfortunately 10 people have tested positive after a family gathering by the Tuesday.”

Little Zak’s Academy in Narellan Vale informed the public of the positive case via a Facebook post on Wednesday morning.

“Since most of our families have already been notified, our centre at Narellan Vale is currently closed for deep cleaning and disinfection after a positive COVID-19 case has been detected last night,” the centre wrote.

“The girl and her family are doing well and resting at home.”

Elsewhere, thousands of families’ school holiday plans are in chaos with Australian states and New Zealand blocking travellers from much of Sydney.

Both Queensland and Victoria have imposed travel bans on people from the seven affected local government areas, causing mass cancellations as the school holidays begin.

Queenslanders returning home from those hotspot areas after 1am on Thursday will be forced to enter hotel quarantine at their own expense.

Non-residents without an exemption will be refused entry to the sunshine state.

-with AAP