Australian police said on Tuesday they were investigating a pro-Palestinian protest outside Sydney Opera House, after footage emerged of a small group appearing to chant anti-Semitic slogans at the demonstration. Around 1,000 pro-Palestinian supporters marched through downtown Sydney on Monday evening to the city's iconic Opera House, which the government had illuminated in the colours of the Israeli flag following Saturday's attacks by Hamas which Israel says killed over 900.

Gaza's Health Ministry said at least 687 Palestinians had been killed in Israeli retaliation air strikes on the blockaded enclave since then. Unverified footage shared by the Australian Jewish Association and featured on Sky News appeared to show a small group outside the Opera House lighting flares and chanting "gas the Jews". Prime Minister Anthony Albanese on Tuesday called the reports of anti-Semitic slogans "horrific".

"We are a tolerant multicultural nation," he said. "I understand that people have deep views about issues relating to the Middle East conflict but here in Australia we have to deal with political discourse in a respectful way." New South Wales state police told a news conference on Tuesday it was reviewing footage from the protest to determine if offences were committed. Protest organiser Palestine Action Group Sydney defended its right to protest "apartheid" in Israel but said a small number of "vile antisemitic attendees" had no place in their movement.

"We are an anti-racist and anti-colonial movement and we refuse to fight racism with racism," the group said in a post on social media. "If you are an antisemite, you are not welcome at our rallies and are not a part of our movement. As we did today, we will ask you to leave and we will continue to do this."