Sydney-siders have been urged to skip an illegal pro-Palestine rally planned for the CBD this weekend, as police admit they “can’t stop 1000 people” if protesters do turn up.

Organisers from the Palestine Action Group Sydney have planned a protest in the city on Sunday night, following Monday’s widely condemned pro-Palestine rally on the steps of the Sydney Opera House.

It was held as the NSW government lit the iconic venue in the blue and white of the Israeli flag in solidarity with victims of terrorist attacks by Islamist group Hamas.

The rally has been widely condemned by police and politicians, as well as one of its organisers, after some demonstrators chanted “f— the Jews” and “gas the Jews”, and burned an Israeli flag at the forecourt of the opera house.

In an unconnected incident, a man was subjected to anti-Semitic threats from passengers in a car that pulled up next to him on a Melbourne street on Tuesday afternoon.

Anti-Defamation Commission chair Dr Dvir Abramovich said he was deeply shocked and the incident should set alarm bells ringing.

“No wonder the Jewish community feels under siege, I am profoundly worried that the massacres carried out against Israelis will now lead to harassment, violence and even worse here in our city,” Abramovich said.

“The ugliness of anti-Jewish hatred is exploding and people are scared that they will beaten and brutalised on the streets and in their businesses.”

He called on the state government and police to continue to respond to hate and stamp out targeted attacks.

More than 1000 people attended a pro-Palestine rally outside the Victorian State Library on Tuesday evening, a day after protesters chanted anti-Israel and anti-Jewish rhetoric at the Sydney rally.

Victoria Police said there were no major incidents or arrests at the Melbourne rally, amid a strong police presence.

On Wednesday, NSW Police acting Commissioner David Hudson said police had set up a task force to capture intelligence about community sentiment, potential protest activity and possible demonstrations that might take place in the future.

“The intent of the operation is to ensure community safety, that is always our primary purpose,” he said.

Hudson said any protest on Sunday would be unauthorised as the relevant paperwork had not been submitted to police within the required seven-day timeframe.

“I would urge anyone considering attending Town Hall, if they have received notification of assembly, that the situation should be monitored closely and we will be doing further communication and negotiations with those organisers,” he said.

“[Protesters] do not have protections that come from the appropriate issue of [the paperwork] and they will be dealt with appropriately.”

If the rally went ahead, Hudson said it would be met with a strong police presence. However, he conceded that authorities could be helpless to stop or block any mass gathering – whether authorised or not.

“We can’t stop a thousand people all gathering at the same place, it would also depend on their behaviour,” he said.

“We don’t have the powers to stop ]thousands of] people from convening at Town Hall.”

The Palestine Action Group has defended its right to protest in Australia, saying media coverage had focused on a tiny fringe of “vile anti-Semitic attendees”.

But Hudson said NSW Police would reject further requests for demonstrations by the group because of Monday’s incident.

“The behaviour has been seen and quite clearly depicted through the media is unacceptable,” he said.

“We can no longer say that that group is responsible for conducting peaceful protests.”

Also on Wednesday, NSW Premier Chris Minns apologised to the Jewish community for the handling of Monday’s demonstration, and said no rally would go ahead.

He said he took “full responsibility” and promised it would not happen again.

“The protest organisers have already proven that they’re not peaceful: shouting racial epithets at Jewish community members is not the definition of a peaceful protest,” he said.

“The idea that they’re going to commandeer Sydney streets is not going to happen.”

NSW Police Minister Yasmin Catley dismissed opposition attacks about her lack of intervention in the protest, saying she had no role in operational policing decisions.

The Jewish Board of Deputies had expressed to her its concerns for safety and requested she stop the rally, she said.

“The decisions are for the police commanders on the ground,” she said.

Minns said the protest was not consistent with Australia’s multifaith, multicultural community values.

“I thought it was abhorrent [for protesters] to occupy the Opera House and scream racial epithets at Jewish community members simply because they’re Jewish,” he said.

A vigil for Israeli victims of the attacks will be held in Sydney’s eastern suburbs on Wednesday night.

Hudson said police would increase their presence around synagogues, Jewish schools and hospitals to ensure people were kept safe.

More than 1000 people are dead after the Islamist group Hamas attacked Israeli towns from the Palestinian territories on Saturday.

Among them was Sydney grandmother Galit Carbone, who was executed at the Be’eri kibbutz, kilometres from the Gaza Strip.

– AAP