Newcastle Rabbi Yossi Rodal has called for kindness and prayers following the invasion of Israel by Hamas militants.
The invasion, which happened on Saturday, has sent fear and anguish through members of Newcastle's Jewish community, many of which have friends and family in Israel.
"It is pretty frightening," said Rabbi Rodal, of Newcastle Hebrew Congregation.
Reports filtered through about the invasion as Newcastle's Jewish community celebrated Simchat Torah - the "second happiest day in the Jewish calendar".
Rabbi Rodal urged people to be "kinder to each other".
"We believe actual prayers and good deeds affect a cosmic change," he said.
"You see the horrible stories of kidnappings of grandmothers and babies, and the terrible barbaric treatment of civilians. Your heart goes out to them."
University of Newcastle Associate Professor Ami Eidels, of the School of Psychological Sciences, has family in Tel Aviv and Ashdod, not far from Gaza.
"I have parents and siblings there, and a daughter who's visiting there now," said A/Prof Eidels, who moved from Israel to Australia in 2008.
His daughter, 21, had recorded a message to say "she is OK for now".
"I'm very concerned. I also have an elderly mother and you can imagine the elderly find it extremely difficult to, for instance, run to shelter when the siren goes off," he said.
"One of the things that frightens me most is everybody's a target. War is horrible. But with terror, they do not distinguish civilians from anyone else."
A/Prof Eidels said the situation in Israel was "unfathomable" when comparing the beauty of things like beaches and lakes in Newcastle.
Newcastle Hebrew Congregation secretary Sam Reich said the war was a "horrible situation".
"I'm grieving for the people who have lost their lives and will lose their lives," Mr Reich said.
"I'm also grieving for a process that seems to have no end. There is so much to be gained by living together in peace.
"Israel and the surrounding Arab nations had been slowly working towards reconciliation and practical arrangements to have relationships to help each other for mutual benefit."
Dr Abdulrazak Mohamad, of Newcastle Muslim Association, said "wars always bring tragedies and human suffering".
"It is sad to have wars and violence in a region meant to be a cradle of peace," Dr Mohamad said.
"Islam is against violating lives, but more so when it comes to innocent human lives. We pray for peace to prevail."
Rabbi Rodal was concerned about the potential for a rise in anti-Semitic activity.
"We rarely if ever experience anti-Semitism in Newcastle," he said.
But there was an incident on Sunday when a group of teens shouted slurs at Jewish people visiting from Melbourne.
"Little kids three to four years old had to hear that stuff," he said.
