Young people are "transmitters of the virus" and warned they are putting other lives at risk after a number of house parties and social outings were caught in the act over the weekend.
It comes as a Professor of Infection Prevention and Disease Control at the University of Sydney warned if we continue to ignore the measures, the worst is yet to come.
In a press conference on Sunday, the Australian Prime Minister Scott Morrison made a direct point to Australians, particularly in their 20s and 30s, who seem to have the "view that because they are healthier that they are not transmitters of the virus".
"They are transmitters of the virus," Morrison said.
"While they themselves may only have a mild case but that is no guarantee, what they are doing by having that view, is that they are putting other people's peoples lives at risk."
Over the weekend a number of young Australians were caught failing to employ social distancing and self-isolation measures, with dozens of people throwing non-compliant house parties across the country.
Guests at one house party in North Parramatta, in Sydney's west, hid in closets and cars until the police left and bragged about it afterwards, yelling out that they were having a coronavirus party.
There are now 3929 confirmed cases across the country.
It comes as new figures show the vast majority of people who have the infection span between the ages of 20 and 69.
"There are still people, whether it is on the beach or congregating in shopping centres, congregating outside, that does not help," the Prime Minister said Sunday.
"We have said very clearly as a National Cabinet that people should not be doing that. You should be going to work and if you cannot work from home, you should be ensuring that when you go outside, you are going to get what you need.
"The idea of people gathering still in groups, this is not helping. People really should not be doing it."
Morrison urged younger people to take heed of his message and pointed to measures taken by police across the country, including on-the-spot fines for those caught breaking the rules.
"You will see the states and territories increasingly enforcing this but it would be much better if did not have to do and we're seeing it among younger people, particularly in their 20s and 30s, and there seems to be a view that because they are healthier that they are not transmitters of the virus. They are transmitters of the virus."
"While they themselves may only have a mild case but that is no guarantee, what they are doing by having that view, is that they are putting other people's lives at risk.
Professor Ramon Shaban, Professor of Infection Prevention and Disease Control at the University of Sydney and Western Sydney Local Health District, said earlier Sunday that if young people continue to ignore social distancing rules, the worst could be yet to come.
"Many Australians around the country have done the right thing over many, many weeks, for which we're all grateful. But there are pockets of individuals, in particular age ranges, who have not done the right thing," he said.
"If that doesn't stop, it's fairly clear to me we'll have much more stringent social distancing measures that'll be applied fairly quickly.
He advised: "The next fortnight is critical for us all if we're going to avoid the kind of wholesale infection and burden of disease we've seen in other countries, such as Italy."
"Many of our deaths have been in elderly folks. But the vast majority of people who have the infection span between the ages of 20 and 69," he said.
"This shows it's important all of us adhere to the measures of social distancing and staying at home."