Health authorities in NSW are concerned about the increasing number of COVID-19 cases where the source is unknown, and have flagged tougher social-distancing measures to combat them.

Key points: Authorities are now focusing on "unknown" community transmissions

Authorities are now focusing on "unknown" community transmissions A Lake Macquarie woman was fined $1,000 for not self-isolating

A Lake Macquarie woman was fined $1,000 for not self-isolating The Premier says she is not allowing her parents to leave their home

NSW Health confirmed 186 new coronavirus infections on Friday, bringing the state's total number of cases to 1,405.

Of that, another 41 cases were confirmed in people who were aboard the Ruby Princess, meaning 162 of NSW's total infections are from that cruise ship.

Earlier this week, NSW Health said another 26 people on the Ruby Princess had tested positive and were interstate, meaning the total number of infections that can be linked to the cruise is almost 200.

The Ruby Princess docked in Sydney earlier this month, and thousands of passengers were allowed to disembark despite several people onboard being tested for the virus.

Today is the second consecutive day the number of new infections has decreased in NSW, but Premier Gladys Berejiklian said the virus was now spreading in a different way.

NSW's Chief Medical Officer Kerry Chant said 145 cases of COVID-19 were acquired from an undeterminable source.

"That is the group that most concerns us because it represents community transmission without a known source," she said.

The number of those unknown transmissions is rising.

Ms Berejiklian said the increasing number of community transmissions would likely mean tougher self-isolation laws.

"When it is community-to-community transmission and you don't have a source, that means the virus is starting to spread in the community without us knowing where and that's a concern," she said.

"We are starting to see an increase in the spread from unknown sources and that's why we are stepping up the compliance, we are stepping up the advice."

She said people exposed to coronavirus via a mystery source might not know to self-isolate, meaning transmissions in the community could continue to increase.

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NSW Police Commissioner Mick Fuller said officers issued a $1,000 fine to a woman in Lake Macquarie yesterday after she refused to self-isolate.

"We have to listen to the message from the Premier and from the Chief Medical Officer if we're going to get through this and minimise the loss of life," he said.

Ms Berejiklian said health authorities were concerned that the amount COVID-19 cases which required intensive care beds could exceed the state's capacity.

"If NSW has to take difficult decisions we will, at a critical stage, to stop the community-to-community transmission," she said.

Several widespread shutdowns have already taken place across NSW and Australia this week, including the closure of restaurants, bars, massage parlours and gyms.

The number of people who can attend weddings and funerals has also been limited.

Ms Berejiklian says people should not go outside unless they "absolutely have to".

She said containing COVID-19 at this stage meant "we are better off in the next few weeks and months".

"It is up to all of us to come together to do our part and deal with the disease at this critical stage," she said.

However, she praised people for listening to the message to stay home, and revealed school attendance during the past week was less than 10 per cent.

She also stressed the importance of vulnerable Australians staying home, revealing that, "in the case of my parents, I haven't let them out of the home and I won't".

"If you're an older or vulnerable person, don't even leave home, but please know that no matter what decisions our state takes in the coming days and weeks, that you will always have a supermarket you can get what you need from," she said.

"You will always have a pharmacy.

"You will always have the essential things that you need to use for your daily health."