The Executive Council of Australian Jewry says the attack at a synagogue in Manchester on the holy day of Yom Kippur is devastating.
British police declared Thursday's deadly car and stabbing attack on the synagogue in the UK's north a terrorist incident.
Two people were killed and another three seriously injured.
Deep connections between the Australian and British Jewish communities go back "almost to the first fleet", according to Daniel Aghion, president of the Executive Council of Australian Jewry.
"The attack in Manchester will be felt very deeply here in Australia because of that — and also because of the fact it was a synagogue attacked on Yom Kippur," he told the ABC.
Mr Aghion said that it had been the experience of Jews around the world, including in Australia, that places of worship, gathering and communal spaces are all secured.
Since Hamas attacked Israel on October 7, 2023, that security had "increased remarkably".
"It is an affront to our society that any Australian has to live this way, but it is the reality of what we face as Jews," Mr Aghion said.
"The Manchester attack, together with the firebombing attacks experienced here in Australia, shows that the risk is real and our fears are justified."
He said that the 2019 attack in the Muslim community in Christchurch, New Zealand, played on his mind this morning.
"I'm not saying for a moment that religious hatred is a zero-sum game, but I'm talking about the currently fomented environment that we, as Australians, are currently living in," Mr Aghion said.
The council's co-executive director, Alex Ryvchin, said Yom Kippur was a special holiday for the Jewish faith, with the community already feeling under threat due to a surge in antisemitism in Australia.
"As we walked to and from synagogue yesterday, everyone would have noticed an enormous police presence, cement barriers at traffic lights to prevent car rammings," he said.
"People wonder why.
"This is why ... it's precisely because what happened in the UK."
The peak Jewish body in NSW said the community was shocked by the fatal terrorist attack.
Michele Goldman, from the NSW Jewish Board of Deputies, said the community will be on edge.
"This is our greatest fear that has now been realised in Manchester," she said.
"We have to make sure we are all being very vigilant."
'It could be Melbourne, it could be Manchester'
For members of the Adass Israel congregation in Ripponlea — in Melbourne's inner south-east — the Manchester attack added to the trauma they are still working through after their synagogue was allegedly burnt down by arsonists in December last year.
Two men have been charged by the Victorian Joint Counter Terrorism Team and ASIO investigators have allegedly linked the fire to the Iranian Government.
"It could be Melbourne, it could Manchester, it could be anywhere in the world, we are feeling this," Adass Israel board member, Benjamin Klein, said.
"Every time it happens then it just refreshes and brings up trauma."
Mr Klein said he and several members of the community went to high school and college in Manchester, and one member of the congregation was close friends with a person who was in hospital after being injured.
"The Jewish community is a very small, close-knit community," he said.
"We're a very small nation … we all know somebody somewhere."
He said the fact the attack happened on Yom Kippur meant the news was delayed in reaching the Adass Israel community.
"Men, women, children, everybody was in the synagogue the whole day," Mr Klein said.
"There was fasting so it was quite a significant and big day and, obviously, no phones or nothing, no communication device or anything like that throughout the day.
"So, we really only found out in the evening when our phones go back on and that's when we started hearing news filtering in from what happened.
"[It] was quite scary, shocking. In fact, this morning in the synagogue, there's lots of conversations around it where people were nervous."
Mr Klein said special prayer services would be held in Melbourne for the victims.
Both Mr Klein and Naomi Levin — chief executive officer of the Jewish Community Council — received phone calls on Friday morning from senior members of Victoria Police to check in with them after the attack.
Ms Levin said she appreciated the outreach at this difficult time.
"We're mourning with the people of Manchester, particularly the Jewish community of Manchester," she said.
"Jewish people, even those who don't usually attend synagogue services, attend synagogue on Yom Kippur. It's the day where we gather as a community and look forward to the year ahead.
"To have our holiest day end with this news of death and terrorism at a synagogue in Manchester was just devastating for all of us here in Melbourne."
Ms Levin called for a global response, saying the Australian Jewish community has been impacted significantly by a rise in anti-Semitism.
"The security at our synagogues over Yom Kippur and the Jewish New Year, which just preceded that, was immense, nothing like I had ever seen before," she said.
"Doors are locked, entry is only by name, there's a guard checking off your name — armed guards at our synagogues.
"Something has to change."
Rabbi Jacqueline Ninio, from Temple Emanuel in Sydney's east, said the Australian Jewish community was mourning the loss of fellow Jews in the attack.
She said the message to her congregation was one of support.
"So many people care for us and support us and are with us and I have received multiple messages today from other faith communities and just ordinary Australians saying 'This is not who we are and this is not what we want in our country'," Rabbi Ninio said.
No place for terrorism: Albanese
Prime Minister Anthony Albanese also condemned the " heinous attack".
"I send my condolences to the people of Manchester after the heinous attack on a synagogue on the most sacred day on the Jewish calendar," he said.
"There is no place for terrorism in our streets and all Australians stand with the UK at this dreadful time."
Opposition Leader Sussan Ley said the Sydney Opera House — where the Palestine Action Group has made an application for a protest for October 12 — was not an appropriate site for the action.
"I just felt sick when I read through what had happened in the UK," she said.
"The terror and the toxic hatred that underpins this hideous antisemitism.
"Now we do need to draw a line in the sand when it comes to the protests that we continue to see in this country, at this point in time is clearly counterproductive."
