The head of ASIO has warned of the potential for violence in Australia as emotions run high over the escalating conflict between Israel and Hamas in the Middle East.

The security agency’s boss Mike Burgess said protests and rallies were expected to continue, and would likely feature strong emotive claims.

“I remain concerned about the potential for opportunistic violence with little or no warning,” said Burgess, director-general of security.

“ASIO is carefully monitoring the situation for any indications of planned violence and were we to see any, we would respond accordingly, along with our law enforcement partners.”

Burgess urged “all parties” to consider their words when making public statements which could inflame community tensions.

His warning came as Opposition Leader Peter Dutton called for the deportation of pro-Palestinian protesters who attended the fiery Sydney Opera House rally.

Dutton said anyone on a visa who attended the demonstration should have it cancelled, as he described the incident as one that would go down in history.

“They should be apologetic to the Jewish community for it. The scenes we saw at the Opera House will be scenes which go down in our country’s history – I don’t think we should underestimate how significantly they’ve been interpreted overseas,” he said on Thursday.

“I don’t want people anywhere in the world to think those scenes represent who we are as a people.

“If they were non-citizens … then their visas should be before the minister, and on character grounds they should have their visas cancelled.”

The Liberal leader’s comments came as organisers of the pro-Palestine rally promised a second planned protest would be peaceful.

Their next public gathering has been planned for the Sydney Town Hall on Sunday afternoon.

The Palestine Action Group Sydney slammed Dutton’s “shocking attack on democratic rights in this country”.

“People have a right to protest against war crimes and apartheid policies of the Israeli state which have been widely condemned by humanitarian organisation and the United Nations.”

Emotions are running high in Australia’s Jewish and Palestinian communities after Hamas launched a brutal surprise attack on Israel which responded with a relentless barrage of rockets.

Man charged

In Sydney, a man was charged over an alleged anti-Semitic incident as Victoria police bolstered security at Melbourne synagogues and schools in line with their NSW counterparts.

The 23-year-old was due to appear in court on Thursday after he allegedly verbally abused four teenagers who unfurled an Israeli flag across their car.

The incident was reported to police on Monday in the eastern Sydney suburb of Bellevue Hill.

On Wednesday afternoon, the man went to Liverpool Police Station and was charged with intimidating with intent to cause fear of physical harm.

NSW Police Minister Yasmin Catley said the state took instances of anti-Semitism seriously and there was no place for any kind of hate.

A second pro-Palestine rally has been organised in Melbourne for Sunday after an investigation into anti-Semitic threats levelled at a bystander from a car in the city’s upscale South Yarra area on Tuesday afternoon.

Police say the man subjected to the abuse is satisfied with their response to the incident and no further action will be taken.

Victorian Premier Jacinta Allan confirmed security would be increased at key locations such as synagogues and schools, following requests.

“This is a very, very difficult time for the Jewish community,” she said in Melbourne.

“We do need to ensure we’re providing a safe and harmonious setting here in Victoria and that is the work that Victoria Police is focused on.”

Thousands of people made a show of solidarity in Sydney’s east on Wednesday night, as the death toll in Israel rose to more than 1000.

Scores of others were taken hostage by the militants after they breached the fence enclosing Gaza on Saturday.

About 5000 people descended upon Rodney Reserve in Dover Heights, many clutching Israeli and Australian flags as well as signs reading “safety is a right” and “united with Israel”.

Rabbi Aron Moss from Bondi’s Nefesh synagogue said the community was reeling from the weekend attack.

“We’re all in pain,” he said.

“Everyone has somebody they know in Israel.

“Everyone here is just one step away from somebody who’s lost their lives or has gone missing so it’s very personal for all of us.”

Jillian Segal, president of the Executive Council of Australian Jewry, addressed a solemn crowd, describing the attacks by Hamas as a “date that will live in infamy”.

“Our world has changed, the barbarians have breached the gates,” she said.

“The butchery and savagery that has unfolded in Israel beggars description … we are totally shattered as we stand together this evening.”

The Jewish community has been on high alert since a cluster of anti-Israeli protests and reports of anti-Semitic threats.

At a pro-Palestine rally on Monday night at the Sydney Opera House some attendees chanted anti-Jewish rhetoric and lit flares.

NSW Police are probing threats against Jewish citizens in Sydney, as well as having dealt with the Melbourne incident.

Rabbi Moss said it was not the Australian way.

“Everyone’s nervous and scared, but we also have a quiet faith that goodness will prevail,” he said.

-With AAP