Protests against Israel's war on Gaza continued outside a defence exhibition in Australia for a second day, after dozens of protesters were arrested and clashes broke out between police and demonstrators on Wednesday.

Australian network News 9 said that tens of thousands of anti-war protesters organized the largest protest in recent years around the site of the Defense Industries Exhibition in Melbourne, demanding that Australia stop arms sales to Israel and end the war on Gaza.

Protesters marched through the streets of Melbourne, where the International Defence Exhibition and Conference is being held, while police set up new barriers to prevent the crowd from entering roads near the venue of the biennial exhibition.

Australian authorities deployed security forces, while police said it was the largest security operation in Melbourne - Australia's second-largest city - since the World Economic Forum in 2000.

Police arrested about 33 protesters yesterday, while using sponge bullets and sound bombs to disperse opponents of arms sales to Israel.

Victoria Police Commissioner Shane Patton said protesters set fire to streets and businesses and damaged public transport, adding that 24 police officers were injured in the attacks.

For his part, Australian Prime Minister Anthony Albanese said that people have the right to protest, but they must do so in a peaceful manner, while the left-wing Green Party called for an independent investigation into the actions of the police.

About 1,000 organisations from 31 countries are taking part in the exhibition, which organisers say is Australia's largest defence exhibition. The three-day event concludes on Friday.