Three people were arrested during clashes between protesters in Melbourne, the capital of the Australian state of Victoria, the Australian Associated Press reported.
A group against transgender rights clashed with hundreds of activists defending these rights at a rally.
Spring Street and the surrounding area remained blocked to traffic for several hours as police, including mounted officers, worked to keep the groups separated.
A Victoria Police spokeswoman confirmed three people were arrested.
A 22-year-old Point Cook man was arrested for allegedly putting a female officer in a headlock and taking her to the ground, while a 23-year-old Thornbury woman was arrested for allegedly slapping a police officer on the neck.
Both are expected to be charged with numerous offences including assault police.
The two officers were uninjured.