Bottles, shoes and other objects were hurled during the clashes with police which resulted in eight arrests, with six police officers injured as the unexpected protest brought parts of the city to a standstill.
“Police stopped the group attempting to enter the MLC centre that houses the American consulate,” police superintendent Mark Walton told reporters of the clash, which left some protesters weeping from the impact of the spray.
Furious protests targeting symbols of US influence flared in cities across the Muslim world on Friday in retaliation for a crude film made in the United States by a right-wing Christian group that ridicules the Prophet Mohammed.
At least six protesters have died in Egypt, Tunisia, Lebanon and Sudan in similar protests against the film, with police there battling to defend American missions from mobs of stone-throwers.
In Sydney, Saturday shoppers looked on in surprise as protesters shouted “Down, down USA” and waved banners such as “Behead all those who insult the prophet” and “Obama, Obama, we love Osama”.
“We are sick and tired of everyone mocking our beloved prophet,” protester Houda Dib told AFP, as the crowd of about 500 gathered outside the US consulate.
“They have no right to mock our prophet. We don’t go around mocking anyone’s religion.”
Demonstrators were pushed back from the steps outside the consulate by police, who then used capsicum spray, provoking anger among some in the crowd, many of whom had brought their children with them.
“They were aggravating the situation by pushing our brothers,” Dib said. “This is supposed to be a peaceful protest.”
But police said while there were peaceful elements in the crowd, others had a different agenda.
“There were elements of the group that were… aggressive, and violent at times and came into conflict with police,” said Walton.
The protesters later moved several blocks away to Hyde Park, where at least one speaker called for calm, saying the aim of their protest — which some demonstrators said they had learned about from Facebook — was to send a message.
“We are here for the sake of our god,” he said. “The message is clear, you cannot mock (the prophet).”
But further clashes broke out with police before the crowd eventually dispersed.
Two police cars were also damaged in the protest which saw some 150 police deployed to the central business district.