Shocking footage shows hundreds of Sydneysiders packed into a concert just hours before masks became mandatory - and hardly any have their faces covered

Thousands of bare-faced revellers have packed a western Sydney theatre sparking concern on social media, as New South Wales' coronavirus outbreak worsens.

Adoring fans flocked to the Sydney Coliseum Theatre in Rooty Hill to see Human Nature perform their greatest hits on Saturday night.

Footage of the crowd showed almost nobody wearing face masks, just hours ahead of a rule change enforcing their use at indoors public venues.

There is no suggestion that the audience members were doing anything wrong as face masks did not become compulsory in Greater Sydney until 11.59pm on Saturday. 

But occupational hygienist Kate Cole flagged her concern about the event's potential to spread the coronavirus on Sunday.

 'I realise that new rules didn't come into effect until midnight last night...but COVID doesn't follow public health orders,' she wrote on Twitter along with a photograph of the bare-faced crowd.

Many in the crowd were not wearing face masks, although they were not mandated until 11.59pm on Saturday so there is no suggestion they were doing anything wrong

Human Nature performing at the Sydney Coliseum Theatre in Rooty Hill on Saturday night 

The Sydney Coliseum Theatre told Daily Mail Australia that it had urged all audience members to wear a mask even though it was not mandatory at the time.

'We strongly recommend masks are worn by any patron 12 years and over. If you do not have one, masks can be purchased at any of our bars for a nominal fee,' they wrote in an email to ticket holders seen by Daily Mail Australia.

Nine News reported that many in the crowd at the 2,200-capacity theatre had been singing along, a danger factor for spreading the virus.

NSW had already barred singing and dancing, and many audience members said that this had been difficult but that they had obeyed the rules. 

Human Nature fans, almost entirely women, took to the Coliseum's FaceBook page to congratulate the theatre for hosting the live music event.

HOW TO CHECK IF YOU NEED A TEST 

There are now 144 separate health alerts for NSW venues on the NSW Health website and 19 for public transport routes. 

The public is urged to check the website here to see if you were at any of those places at the red-flagged dates and times.

If you were there at the times flagged, you may have come in contact with the virus and may need to isolate and get tested. 

They were grateful just to be able to see the band even if they couldn't sing along. 

'Thank you Coliseum for doing a great job! As hard as it was not singing and dancing, it's a small sacrifice to still see the boys,' wrote one woman.

'Loved it. So hard to stay in your seat and not sing,' wrote another.

Many in the audience instead had to 'chair dance', waving their arms as rapturously as they were allowed.

 'Thoroughly enjoyed the show had an amazing night - missed live music so much so happy it went ahead,' wrote one.

As of 11.59pm on Saturday night, residents across Greater Sydney, which includes Wollongong, Central Coast and Blue Mountains, were required to cover up with a face mask in public places.

Although the rule has come into effect, enforcement only begins until Monday.

Anyone caught not wearing a mask within public indoor settings risks a $200 fine from Monday onwards.

Children aged under 12 years are not required to wear a mask, though it is strongly encouraged.

It is compulsory to wear a mask in some indoor places including shopping centres and cinemas, and on public transport - which includes trains and buses.

Residents visiting an entertainment venue, hair and beauty salons, gaming areas or places of worship will also have to follow the rules.

Hospitality staff also have to wear a mask while serving customers.

New South Wales recorded eight new coronavirus cases in the 24 hours to 8pm on Saturday with an additional three cases in returned travelers in hotel quarantine.

Many were glad to see the show even though they weren't supposed to sing and dance

 The crowd at the 2,200-capacity theatre were well behaved and stayed in their seats

The Sydney Coliseum Theatre in Rooty Hill was praised by fans for letting the concert go ahead, however some were alarmed at the potential for the virus to spread

The crowds 'chair danced' to their favourite songs, waving their hands as they weren't allowed to dance. Masks are now mandatory in public indoor settings in Greater Sydney

There are now 125 active coronavirus cases with NSW Health concerned about the growing Berala cluster linked to a BWS bottle shop.

On Saturday evening, NSW Health ramped up its alert for liquor store, with many of its customers of the Christmas holiday period now considered to be close contacts.

The alert for the BWS now covers long periods on every day between December 22 and New Year's Eve, except Christmas Day.

Greatful fans thanked the Coliseum and said they had stopped themselves from singing and dancing along to Human Nature on Saturday

Chief Health Officer Kerry Chant said anyone who attended the BWS at at those times should get tested immediately and isolate for 14 days regardless of the test result. 

In good news, NSW Health has told Daily Mail Australia that none of the locally acquired NSW cases are of the new mutated variant of the virus found in the UK and South Africa. 

When to wear a face mask

New South Wales premier Gladys Berejiklian announced face masks would be mandatory for all Greater Sydney residents from 11.59pm on Saturday.

The rule also applies to residents living Wollongong, Central Coast and Blue Mountains.

Whenever a resident leaves their home, they will need to wear a mask when visiting these indoor settings:

1) Entertainment venues, such as a cinema

2) Places of worship, such as a church or mosque

3) Public transport, such as buses and trains

4) Shopping centres

5)  Established gaming areas

6) Hair and beauty salons

Anyone who is caught not wearing a face mask risks copping a $200 fine. 

Scientists at London's Imperial College say the new strain, called 'Variant of Concern 202012/01' is almost twice as infectious as the ordinary virus, and it is rapidly taking over and becoming the pandemic in London.

There are now 144 separate health alerts for NSW venues on the NSW Health website and 19 for public transport routes.

The public is urged to check the alerts on the website here to see if they were present at the red-flagged dates and times where they might have picked up an infection, and therefore need to isolate and get tested.  

Acting NSW Premier John Barilaro said testing rates dramatically plunged, and urged all residents to get tested even if they have only mild symptoms. 

'We do need to increase that number of testing,' he told reporters on Sunday.

'The success of this state has come off the back of the large number of testing that's been happening right across the state.

'Even though we are thankful for the 18,927 that came forward, we want to see those numbers get up, close to 20,000 or 30,000 people.'

NSW Health Minister Brad Hazzard said an alarming amount of people may have been exposed to the virus in the area around Berala.

'We're asking people from that area particularly to come forward and get tested... just over 18,000 people being tested is not what we would hope for,' he said.

'We've seen what Sydney can do, and Sydney can rise to the occasion. We're asking all of the community in western and south-west Sydney, or indeed in Wollongong to rise to the occasion again and go out and get tested.'