Thousands of anti-Islam and anti-racism protesters have clashed in rallies around Australia.

The most violent was in Melbourne, Australia's second-largest city, where police struggled on Saturday to separate opposing demonstrators.

Ambulance Victoria spokesman Paul Bentley says the Victoria state ambulance service treated four people, three for minor injuries, from assaults in Melbourne. The fourth was treated for chest pains.

Victoria Police spokeswoman Belinda Batty says police arrested two men and a woman in the fracas in Melbourne's downtown Federation Square.

Reclaim Australia, a community group, organized rallies in 16 cities and towns around Australia against Islamic extremism, the "Islamization" of Australian society, Islamic Sharia law and the Halal-certification of most meats sold in Australia.