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.
One police officer suffered minor injuries after being 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, which local media estimated had involved between 150 and 200 people.