Police use stun grenades and pepper spray and arrest 39 people as officers pelted with rocks, manure and tomatoes.

Antiwar protesters have clashed with police outside an arms fair in the Australian city of Melbourne as they demanded a change in Canberra’s stance on the Israel-Gaza conflict.

Police said they used stun grenades, pepper spray and “rubber bullets” and arrested 39 people on Wednesday, as about 1,200 picketed the Land Forces 2024 military weapons exposition. Australia has seen numerous protests against the country’s arms industry’s involvement in Israel’s war on Gaza over the past 11 months.

“We’re protesting to stand up for all those who have been killed by the type of weapons on display at the convention,” Jasmine Duff from organiser Students for Palestine said in a statement.

About 1,800 police officers were deployed to the Melbourne convention centre hosting the three-day weapons exhibition. Up to 25,000 people had previously been expected to turn up at the protest.

Protesters pelted officers with rocks, horse manure and bottles filled with liquid irritants, some of which were identified as acid, leaving two dozen requiring medical treatment, said a Victoria state police spokesperson in a statement.

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

Arrests were made for a range of offences, including assaulting, obstructing or hindering police, arson and blocking roads, said the statement, adding that police were “appalled” by the behaviour of protesters.

The Wage Peace – Disrupt War group, which was involved in the protests, said on its Facebook page that it had made its message “loud and clear”.

The group reported that police had used “extreme weaponry” throughout the protests, including pepper spray, flashbangs (or stun grenades) and rubber bullets.

Chief Commissioner Shane Patton said that “rubber bullets” reported as being used during the protest were hard foam baton rounds.

“We’ve used these before, our tactical police are trained in them,” he was quoted as saying by the Australian Broadcasting Corporation.

Prime Minister Anthony Albanese said people had the right to protest but had 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,” Albanese told Australia’s Channel Seven.

Australian media reported the police operation in Melbourne was the largest since 2000, when Australia’s second largest city hosted the World Economic Forum.

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