Tens of thousands of Australians defied government calls to stay at home Saturday by spilling onto the streets for Black Lives Matter protests in major towns and cities across the country.

Marchers in Sydney, Melbourne and elsewhere rejected arguments from law enforcement and conservative leaders that mass protests could fuel the spread of coronavirus.

Marchers defied government warnings about coronavirus to rally in Sydney Marchers defied government warnings about coronavirus to rally in Sydney Photo: AFP / SAEED KHAN

A court on Friday declared the Sydney protest illegal on health grounds, although the ruling was overturned by an appeals court minutes before the march was due to start.

"The fact that they have tried to push us all back and stop the protest, it makes people want to do it even more," said Jumikah Donovan, one of thousands who turned up thinking the ban was still in place.

Protesters were also out in force in Brisbane Protesters were also out in force in Brisbane Photo: AFP / Patrick HAMILTON

The Sydney march was largely peaceful, although one "All Lives Matter" counter-protester was taken away by police.

Demonstrators brandished signs that read "I can't breathe", a nod to the last words of African-American man George Floyd, whose death while being arrested has sparked civil rights protests around the world.

Another read: "Same story, different soil."

Many protesters wore face masks, brought hand sanitiser and tried to social distance Many protesters wore face masks, brought hand sanitiser and tried to social distance Photo: AFP / Patrick HAMILTON

The movement has resonated strongly with many in Australia -- a country also wrestling with the legacy of a racist past.

Organisers said they hoped to highlight the high rates of imprisonment among Aboriginal Australians and large number of deaths in custody of indigenous people -- more than 400 in the last three decades.

Protesters march in Sydney in solidarity with US Black Lives Matter demonstrators, and to demand an end to Aboriginal deaths in custody Protesters march in Sydney in solidarity with US Black Lives Matter demonstrators, and to demand an end to Aboriginal deaths in custody Photo: AFPTV / Andrew LEESON

No prosecutions have been brought despite dozens of investigations, inquests and in some cases video evidence of abuse.

Many of the protesters wore face masks, brought hand sanitiser and tried to social distance as best they could.

"There are things in the world that need to be addressed," said Fay Goli. "If one person can stand, that's great, but if a majority can stand together there will be a stronger voice for change."

Australia has seen a sustained drop in the number of COVID-19 cases, but social distancing rules remain in force and mass gatherings are not permitted.

"Police are prepared for anybody that wants to just flout the law," New South Wales Police Minister David Elliott told media before the rallies.

Protesters in Melbourne were warned they could face fines for attending a rally if social distancing was not observed, although police appeared not to be enforcing those rules.

The day before the protests Prime Minister Scott Morrison had urged people to stay home.

He admitted there was more to be done to address indigenous inequality, but rejected parallels with the United States.

"Australia is not other places, so let's deal with this as Australians and not appropriate what's happening in other countries to our country at this time."