Shhhh! Cricket fans urged to cheer quietly at SCG amid COVID outbreak

Australian authorities are asking fans at the Sydney Cricket Ground (SCG) not to cheer too loudly during the third test against India next week as the city grapples with an outbreak of COVID-19.

The New South Wales (NSW) government restricted movement and tightened curbs on gatherings in Sydney on Wednesday, as the state recorded 18 new cases.

Despite public gatherings being capped at 30, authorities have given the green light to a half-capacity crowd at the 48,000-seat SCG, though fans will be asked to keep a lid on their cheering.

"We will be handing out masks on public transport going into the SCG, and advising people to wear masks when they are not physically at their seat," New South Wales Chief Health Officer Kerry Chant told a media briefing on Wednesday.

"We also are asking people to ensure that they recognise (rules) around screaming and chanting, particularly when they are not in their fixed location."

After weeks without a new case of COVID-19, NSW has recorded more than 100 infections linked to a recent outbreak in the city's northern beaches.

Governing body Cricket Australia considered moving the third test to Melbourne but on Tuesday confirmed it would plough ahead with Sydney as scheduled from January 7.

The players and staff are in Melbourne following the traditional 'Boxing Day' test, which India won on Tuesday by eight wickets, levelling the four-match series at 1-1.

To mitigate risk, they will stay in Melbourne longer than planned before arriving in Sydney a couple of days before the match starts.

They will also be subject to stricter biosecurity protocols in Sydney, and for the fourth test in Brisbane.

Australia paceman Pat Cummins said it would be hard for some of the players, a number of whom have not spent time with family for months while touring.

"We'll look after everyone as best we can but the priorities are getting through this series safely and everyone's desperate to play these last two tests," Cummins told reporters on Wednesday.