Two new cases of coronavirus have been diagnosed in NSW with both linked to a bottle shop cluster in Sydney's west, prompting the chief health officer to issue an urgent warning.

The two cases were diagnosed after the 8pm cut off and will be included in Tuesday's numbers, meaning there were zero local cases recorded on Monday, for the first time since December 15.

One case linked to the cluster is a man in his 40s who visited the BWS in Berala and the other is a woman in her 40s who "has links" to the BWS and Woolworths in Berala, Dr Kerry Chant confirmed.

But her case remains under investigation.

A BWS employee worked for nine days while unknowingly infectious after an infected customer visited the store.

"The person who entered the BWS … they had no symptoms and no reason at all to think they had a COVID infection," Dr Chant said.

"It is really important that we all bring that to mind any time we're out and about, someone could have COVID and that's why we need those universal precautions of keeping that physical distancing and the mask-wearing particularly in those indoor settings.

"There will be positive people in any setting you go in.

"No one knowingly spreads COVID."

Dr Chant said a patient transport worker contracted the virus and passed it to a close contact who went into BWS while unknowingly infectious.

Chief health officer Dr Kerry Chant warned anyone could have COVID after asymptomatic person unknowingly starts new cluster. Picture: NCA NewsWire/Flavio Brancaleone
Chief health officer Dr Kerry Chant warned anyone could have COVID after asymptomatic person unknowingly starts new cluster. Picture: NCA NewsWire/Flavio Brancaleone

More than 22,000 tests were conducted in the latest reporting period, which deputy premier John Barilaro said was "far too low".

"We need to increase those numbers," he said, highlighting the enormity of tests done when the northern beaches outbreak first became known.

He is urging western Sydney residents to get tested.

Figures come as the rules around mandatory masks come into force.

Anyone caught indoors, including in shopping centres, churches and cinemas, without one will be fined $200.

Children younger than 12 are exempt but are encouraged to wear masks when possible.

Originally published as 'Anyone could have it': cluster warning



Horse trainer ‘distraught’ over lack of care for animals

Premium Content Horse trainer ‘distraught’ over lack of care for animals

RSPCA and Racing Queensland inspectors found horses living in terrible conditions...

Veterans Lounge tackles defence family issues

Premium Content Veterans Lounge tackles defence family issues

A charity for defence families is about to launch a new gambling and alcohol-free...

Ipswich suburb pushing for Neighbourhood Watch program

Premium Content Ipswich suburb pushing for Neighbourhood Watch program

Police are receiving phone calls from residents eager to get meetings up and...