NSW has recorded another spike in locally acquired Covid-19 cases with a further 16 announced on Wednesday.
Wednesday's official total is 10, seven of which were announced on Tuesday.
NSW Health has identified 13 new cases after 8pm last night that will be included in Thursday's numbers.
The number of local cases now stands at 37 since the virus was first detected in a limousine driver who transported air crew.
The Bondi cluster stands at 31 cases.
"[This variant] is extremely contagious... this is clearly a big threat to our state," Premier Gladys Berejiklian told reporters.
Eight of the 16 new cases are linked to a birthday party at West Hoxton attended by a previous case in the Bondi cluster.
One of those cases is a two-year-old child from a daycare centre in Narellan Vale, 60km southwest of the Sydney CBD.
There are now 10 cases linked to the party, with Chief Health Officer Dr Kerry Chant saying under her definition it is deemed a super-spreader event.
A further four unlinked cases have been identified, adding to the St Charles Primary School case without a source.
Dr Chant said on Tuesday it was a "positive" sign the existing cases were from the same geographical area, with health authorities now scrambling to contain the virus from spreading further.
Dr Chant had anticipated another sharp rise saying it was likely household contacts of existing cases would test positive in the coming days due to how transmissible the Delta variant is.
Restrictions tightened further
Ms Berejiklian announced a further tightening of restrictions on Wednesday to combat the surge in cases.
"Please abandon non-essential activities, please don't attend social gatherings unless you absolutely must," the premier said on Wednesday.
"I am not going to rule out further action."
Notably households in Sydney, Central Coast, Shellharbour, the Blue Mountains and Wollongong will not be allowed more than five visitors at a time from 4pm today.
"This is no time for game playing, it is no time for stupidity. This is a very serious situation that we are now in," Health Minister Brad Hazzard told reporters.
Anyone living or working in the 7 LGAs banned by Queensland and Victoria — the City of Sydney, Woollahra, Bayside, Canada Bay, the Inner West, Randwick and Waverley Council — will not be allowed to leave metropolitan Sydney.
At bars and restaurant, all patrons must be seated and cannot mingle.
The state has also reverted to the 'one person per four square metres' rule, which will impact funerals and weddings.
Masks are now compulsory in non-residential indoor settings - including workplaces - and at outdoor events.
Masks must also be worn to gym classes, which limited to 20 people.
Promisingly, there were more than 44,000 tests were completed in the previous 24-hour reporting period.
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