Police say 218 people were arrested and six officers were hospitalised after today's violent anti-lockdown protests in Melbourne.
A Victoria Police spokesperson said more than 4000 people attended the protest.
Thousands of demonstrators were seen breaking police lines near Parliament House in Spring Street, where the demonstration started.
Violence erupted as mostly unmasked demonstrators moved through the CBD towards Flinders Street station, letting off flares and chanting slogans.
The most violent scenes were seen at Flinders Street, with protesters throwing objects at police, who responded with pepper spray.
"While there were some peaceful protestors in attendance, the majority of those who attended came with violence in mind," a Victoria Police spokeswoman said.
"The behaviour seen by police was so hostile and aggressive that they were left with no choice but to use all tactics available to them.
"For the first time during lockdown protests, police were forced to use a range of non-lethal options including pepper ball rounds and OC foam cannisters in an effort to disperse the crowd."
The spokeswoman said seven police officers were injured during the demonstration - two with suspected broken noses, one with a broken thumb and the rest with concussions.
Some demonstrators blasted music and many yelled anti-lockdown slogans, while others held up placards alluding to unrelated conspiracy theories.
The bulk of the protest had dissipated by mid-afternoon.
Police arrested 218 people, including three in custody for assaulting officers, and issued 236 fines.
Each person arrested will be fined A$5452 for breaching lockdown restrictions, the spokeswoman said.
Investigations will continue into the protest.
Earlier, Victoria Police Chief Commissioner Shane Patton urged people not to attend the protest.
"It is tagged as it is a 'freedom demonstration'. It's anything but," he said.
A statewide lockdown came into force from 1pm in response to a growing cluster in Shepparton in the state's north-east and a rising number of mystery cases in Melbourne.
Authorities have been increasingly concerned coronavirus is spreading undetected in the community, with cases now spread right across Melbourne and more than 500 exposure sites.
"Protesting doesn't work against this virus," Premier Daniel Andrews said.
"In fact, it may well contribute to the spread of this virus. And the more cases we have, the longer we'll be locked down."
Anti-lockdown protests held in Sydney, Brisbane
Police have also arrested people attending a similar protest at Victoria Park in Sydney's inner-west.
There had been a heavy police presence around Sydney's CBD in anticipation of the demonstration.
More than 2000 anti-lockdown protesters gathered in Brisbane's Botanic Gardens before a planned march through the city.
The event was largely peaceful, compared to the clashes in Sydney and Melbourne.
There were smaller gatherings in other cities such as Darwin.