Australia's deadliest day of coronavirus has medical experts scrambling for answers and the prime minister warning of possible new restrictions.
Scott Morrison has sounded a coronavirus warning to churchgoers and those celebrating the Islamic holiday Eid al-Adha.
The prime minister, who is a devout Christian, said he and wife Jenny had not been to church in months.
"I know faith is very important to people, but even at times like this, it's even more important that we don't gather in those large groups," he told 2GB radio on Friday.
"As important as faith is, that we really do think of the health issues here.
"I just want to encourage everyone to make positive decisions when it comes to how they choose to celebrate their faith over this important time for that (Islamic) community."
NSW has granted an exemption for 400 people to gather at a mosque in western Sydney to celebrate Eid, which takes place this weekend.
Everyone who attended the Auburn Gallipoli Mosque on Friday morning had to wear a mask, had their temperature checked and abided by social distancing rules.
Meanwhile, four more Sydney venues have been shut down for deep cleaning and contact tracing after being linked to coronavirus infections.
Sydney travellers are rushing to cross the border into Queensland before they are locked out.
The prime minister praised the NSW government for their swift response to new cases.
Unlike Victoria, there are no active cases in NSW with an unknown source.
"But that can change," Mr Morrison said.
The prime minister acknowledged authorities were not yet on top of coronavirus outbreaks in Victorian nursing homes, describing the situation as overwhelming.
He and Victorian Premier Daniel Andrews spoke at length overnight to discuss the possibility of harsher lockdowns.
Federal Finance Minister Mathias Cormann is bracing for harsher measures.
"I certainly expect restrictions will be further tightened to ensure we ring-fence the areas of outbreak," he told Sky News.
Deaths and new cases surged to record levels in Victoria on Thursday, with the loss of 13 more lives pushing the national toll to 189.
The state recorded 723 new cases, prompting the premier to make face masks mandatory for all Victorians.
The Australian Health Protection Principal Committee provided advice on further measures to stop the outbreak to federal and state leaders on Thursday night.
Mr Morrison backed the Victorian government's move to ban people visiting each other in six regional shires.
"We can't rule out further restrictions or limitations to stem this outbreak," he said.
NSW recorded 18 new cases, with just two coming from returned travellers in hotel quarantine.
Queensland had one overseas-acquired case and three locally acquired.
South Australia had one local case and WA recorded an overseas case.
Mr Morrison will hold a phone hook-up with premiers and chief ministers on Friday to discuss national security matters.
National cabinet is due to meet again next Friday.
People in Australia must stay at least 1.5 metres away from others. Check your state’s restrictions on gathering limits.
If you are experiencing cold or flu symptoms, stay home and arrange a test by calling your doctor or contact the Coronavirus Health Information Hotline on 1800 020 080.
News and information is available in 63 languages at sbs.com.au/coronavirus