Melbourne has become a battleground of competing ideologies, with a rally by the Reclaim Australia movement and counter-protest by the left-wing No Room for Racism group.
Tempers flared as a Reclaim Australia supporter scuffled with a Guy Fawkes mask-wearing socialist protester.
More than 100 officers put up a line of bodies to separate the two groups.
Eleven horses from the mounted division were also used to hold the crowds apart in Flinders St, as scuffles broke out across the square.
Reclaim Australia members claimed to be protesting against the rise of Islamic extremism and sharia law in Australia.
Several protesters tried to break the police line, and at least two man were heavily restrained by the police.
One policeman confiscated a long piece of wood from someone at the rally.
Police formed a corridor to corral Reclaim Australia supporters through the angry crowds as the really drew to an end.
Counter-demonstrators tried to slow the exit, hurling abuse as the Reclaim attendees move through the throng.
Reclaim Australia’s speeches included an address by proclaimed “human rights expert” Daniel Nalliah.
The group’s numbers grew significantly throughout the rally, but they were still outnumbered by socialist counter-demonstrators.
A massive cheer erupted among the Reclaim supporters as a group of members wearing blue singlets and war medals were let through to join their brethren.
“You said I wouldn’t get in — who’s he d—head now?” yelled one Reclaim supporter.
The Reclaim members sang renditions of Advance Australia Fair, but the anti-racism protesters’ chants of “immigrants are welcome, racists are not” could also be heard throughout the CBD.
In Brisbane, the rally protesting Islam has caused a tense stand-off between opposing ideologies in King George Square.
Between 200 and 300 protesters and a large turnout of police have gathered in the CBD’s centre, chanting and waving banners.
While in Sydney, on either end of Martin Place, separated by a wall of police, anti-racist and anti-Islam protesters have faced off near the scene of last year’s Lindt Cafe siege.
On the lower end braving the rain on Saturday were vocal supporters of Reclaim Australia, a group pushing nationwide rallies against “sharia law, halal tax and Islamisation”.
Many of the flag-waving crowd-goers, in the hundreds, chanted “Aussie, Aussie, Aussie — Oi, Oi, Oi” and were carrying homemade banners denouncing sharia law like in Melbourne and Brisbane.
But it was a proposition those in the anti-racist rally corner labelled absurd.
“There is no possibility of sharia law in Australia, that is absolutely ridiculous,” Tony Iltis said.
Mr Iltis was part of a smaller but passionate crowd that slammed Reclaim Australia’s “racist” slant.
“Basically they are neo-nazis who are able to not look like neo-nazis because the mainstream has become so racist,” Mr Iltis said.
“I think the Muslim community needs to know that not all Australians are racist. I think they feel intimidated and how the Jews felt in the 1930s.”
Tensions almost erupted when a woman ran on stage at the Reclaim Australia camp, grabbed the microphone and told the crowd they should be ashamed.
Riot police were quick to respond and quell any clashes.
Among the Reclaim Australia crowd, many sporting Australiana memorabilia, was Greg and his home-made sign that compared sharia law to paedophilia.
“I’m just standing up for our freedom of speech and way of life,” he said, wearing a green and gold shirt.
Rally organisers deny Reclaim Australia is racist, but say protesters have a problem with Islamic extremists who want to live by sharia law.
Event organiser Sarah Spearpoint says, like her, moderate Muslims also don’t accept extreme views of their religion.