Thousands of Australians joined pro-Palestinian rallies on Sunday, organisers said, amid strained relations between Israel and Australia following the centre-left government’s decision to recognise a Palestinian state.

More than 40 protests took place across Australia on Sunday, Palestine Action Group said, including large turnouts in state capitals Sydney, Brisbane and Melbourne.

The group said around 350,000 attended the rallies nationwide, including around 50,000 in Brisbane, though police estimated the numbers there at closer to 10,000. Police did not have estimates for crowd sizes in Sydney and Melbourne.

In Sydney, organiser Josh Lees said Australians were out in force to "demand an end to this genocide in Gaza and to demand that our government sanction Israel" as rallygoers, many with Palestinian flags, chanted "free, free Palestine".

Alex Ryvchin, co-CEO of the Executive Council of Australian Jewry, the umbrella group for Australia's Jews, told Sky New television that the rallies created "an unsafe environment and shouldn't be happening".

The protests follow Israeli Prime Minister Benjamin Netanyahu this week stepping up his personal attacks on his Australian counterpart Anthony Albanese over his government's decision this month to recognise a Palestinian state.

Diplomatic ties between Australia and Israel soured after Albanese's Labor government said it would conditionally recognise Palestinian statehood, following similar moves by France, Britain and Canada.

The August 11 announcement came days after tens of thousands of people marched across Sydney's iconic Harbour Bridge, calling for peace and aid deliveries to Gaza, where Israel began an offensive nearly two years ago after the Hamas militant group launched a deadly cross-border attack.

Palestinian authorities say the conflict has claimed the lives of more than 60,000 people in Gaza, while humanitarian organisations say a shortage of food is leading to widespread starvation.