SYDNEY – Anti-war protesters and police clashed outside a defence exhibition in Australia’s second-largest city of Melbourne on Sept 11, with dozens arrested as police used sponge grenades, flash-bang devices and irritant sprays to control parts of the hostile crowd.

Police were pelted with rocks, horse manure and bottles filled with liquid as they tried to protect attendees of the expo, some of whom were assaulted by protesters, said a Victoria state police spokesman in a statement.

Two dozen police officers required medical treatment and 39 people were arrested for offences that include assaulting, obstructing or hindering police, arson and blocking roads, Victoria Police Chief Commissioner Shane Patton told reporters.

Protesters lit fires in the street, disrupted traffic and public transport, while missiles were thrown at several police horses but no serious injuries were reported, police said.

Some police officers were spat at by protesters, while others were sprayed with a liquid irritant, some of which was identified as acid, Mr Patton added.

“This is the type of disgusting behaviour that we saw today from a group who were intent on confronting us,” he said.

“If you wish to come and protest, do so peacefully. We will not tolerate criminal behaviour.”

About 1,200 people attended the protest outside the venue hosting the biennial Land Forces International Land Defence Exposition, the authorities said.

Many chanted pro-Palestine slogans through loudspeakers and waved Palestine flags, while others had signs and flags representing other conflicts and causes, video footage showed.

Dumpsters were pushed towards police lines, and one protester climbed on top of a truck that had stopped at traffic lights.

Australian media reported that it was the largest police operation in Melbourne since 2000 when the city hosted the World Economic Forum.

About 1,000 exhibiting organisations from 31 countries are expected to attend the event through Sept 13, which the organisers said was Australia’s largest defence expo.

Some attendees were doused in a red liquid by protesters, ABC News reported.

Prime Minister Anthony Albanese said people have the right to protest, but they have to do it in a peaceful manner.

“You don’t say you’re opposed to defence equipment by throwing things at police. They’ve got a job to do and our police officers should be respected at all times,” Mr Albanese told Channel Seven. REUTERS