Protesters have ignored pleas to stay home during the coronavirus pandemic.
People met across eight Melbourne locations on Saturday to call for freedom for refugees stuck in indefinite detention.
At a hotel in the northern suburb of Preston, Mantra Bell City, where some refugees have been held for at least seven months, up to about 30 protesters were pictured standing outside.
Asylum seekers who were transported from Manus Island for medical treatment peered out of hotel windows to watch the rally.
A former refugee from Sri Lanka told the protesters in a speech that detention centres and hotels housing asylum seekers are "basically prisons designed to inflict pain on people whose only crime is to seek asylum".
The protesters unfurled a banner off the side of a house facing the hotel which reads: "Free the hostages from Mantra Hotel, they are not criminals".
A small number of South Australians also defied coronavirus restrictions by attending a Black Lives Matter rally, despite the protest being cancelled after an exemption for the event was denied.
Police officers, mounted on horses, watched over Victoria Square in Adelaide's CBD on a wet Saturday as about 30 protesters chanted while holding signs and wearing masks.
There was no indication that anyone was warned or fined as a result of their behaviour.
Gina, 20, says she was not intimidated by authorities but had been expecting a larger turnout.
"Civil unrest is what sparks change," she said.
"We have to continue to fight even if they say you can't.
"We're taking all the precautions; wearing masks and having hand sanitiser."
Kalli Samaras, 25, who protested in last weekend's rally, said work commitments stopped her from attending, not the event's cancellation or the possibility of being penalised.
Under South Australia's directions, those who breach COVID-19 restrictions will receive a $1000 fine.
"I hope people attended (because) the experience was really empowering and emotional," Ms Samaras said.
"We need to support these causes and educate as many people as we can about these issues.
"They are not only black issues, these are our issues and we need to work together to stop inequality, injustice, stereotypes and racism."
Police Commissioner Grant Stevens had previously warned of a police presence, saying officers would be ready to deal with "any eventuality".
"As we've done with every restriction imposed on the community, we'll seek to work with those people, provide them advice and give them an opportunity to comply with the directions before we consider taking any further steps," he said.
On Wednesday, organisers cancelled the second rally but vowed to return to the streets in the future.
A crowd of more than 5000 attended last weekend's protest in Victoria Square, calling for justice over the death of American man George Floyd and an end to Aboriginal deaths in custody.
The ABC reported about 1000 people turned up to Perth’s Langley Park on Saturday for a Black Lives Matter protest.
It was originally estimated up to 15,000 people would attend.
In Sydney, less than 200 rallied at Town Hall about 2pm, The Daily Telegraph reported.
The Supreme Court on Thursday night night ruled it a prohibited public assembly.
NSW Police opposed the event on health grounds amid the coronavirus pandemic, warning they could not guarantee against the spread of the potentially deadly disease at the event.
Justice Walton Michael Walton ruled that the public health risks did not outweigh "the rights to public assembly and freedom of speech in the present context".
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