Two people have been arrested after protesters clashed outside an Australian event hosted by ultra-conservative figure Milo Yiannopoulos.
Riot police moved in when tensions between opposing protest groups escalated in Melbourne on Monday night.
Five police officers suffered minor injuries - one was hit by a rock.
Mr Yiannopoulos, a UK writer who has been criticised over videos in which he appeared to condone paedophilia, is in Australia for a speaking tour.
Protesters from Campaign Against Racism and Fascism and opposing groups, including the anti-Islam Reclaim Australia, were involved in the street skirmish. Some brandished sticks and threw glass bottles.
Police used capsicum spray in a bid to quell the confrontation. They said at least 330 people took part in the protests.
"Both sides need to have a good hard look in the mirror at themselves," Victoria Police assistant commissioner Stephen Leane said on Tuesday.
"The right side came in smaller numbers and... they set about early to agitate."
He said one person on each side was arrested, and further arrests could be made.
Mr Yiannopoulos told local radio station 2GB that he blamed left-wing protesters for "being violent to stop people's speech".
"The left really showed us who they are. They attack the police, they attacked other people, they attacked journalists - they showed us they are petulant babies."
He will speak at a private event in Canberra's Parliament House on Tuesday following an invitation from an independent senator, David Leyonhjelm.
Last week, the left-wing Greens party called for Mr Yiannopoulos to be banned from speaking in Canberra - citing what they called his "racist, sexist and abusive behaviour" - but were unsuccessful.
The self-described "supervillain" is regularly associated with the alt-right, a disparate nationalistic group that is outspoken against so-called political correctness and feminism - although Mr Yiannopoulos has said he does not consider himself part of it.
But many critics point out that his comments on subjects such as Islam and feminism are consistent with far-right movements in the US.
In February, Mr Yiannopoulos lost a book deal after footage showed him discussing the merits of gay relationships between adults and boys as young as 13. He denied ever endorsing paedophilia.
In 2016, he was banned from Twitter for "inciting or engaging in the targeted abuse or harassment of others", after actress Leslie Jones suffered a barrage of abuse from other users.