Synagogue arson attack sparks manhunt, security plea

Political and religious leaders have unanimously condemned an anti-Semitic arson attack on a synagogue built by Holocaust survivors, as security is beefed up around Jewish communities.

Police are hunting two masked arsonists who allegedly broke in, poured accelerant and set one of Melbourne's biggest synagogues alight in the early hours of Friday, while congregants were preparing for morning prayers.

The Adass Israel synagogue in Ripponlea was engulfed in flames just after 4am, gutting two of its three buildings and leaving two people with minor injuries.

The Jewish community had lived in fear for the past 14 months, Executive Council of Australian Jewry president Daniel Aghion said.

"This for us is just evidence of that fear," he said.

"This is a tragic day for the Australian Jewish community."

Victorian senator James Paterson said police and the government needed to boost security to reassure worshippers.

"There will be other shuls and synagogues in the area tonight contemplating Friday night prayers and wondering whether they're safe to do so," he said.

Victorian Premier Jacinta Allan confirmed police patrols would be increased from Friday into next week, as she pledged $100,000 towards rebuilding the synagogue.

"This is a place of worship that was built by Holocaust survivors who fled that most evil regime in Europe and chose Melbourne as their home," she told reporters on Friday afternoon.

"An attack on a place of worship is an attack on all faiths."

Prime Minister Anthony Albanese echoed the premier's sentiment, saying "to attack a synagogue is an act of anti-Semitism".

He confirmed he had spoken with the head of the Australian Federal Police about ensuring all resources requested were available for the Victoria Police investigation.

Israel's ambassador to Australia Amir Maimon said the "outrageous" attack served as a chilling reminder anti-Semitism was not a relic of the past.

"'Never again' has become a hollow promise as the very evils it sought to prevent are happening once more," he said.

Religious organisations, including the Australian Federation of Islamic Councils, decried the "disturbing" incident and shared their sympathies with the Jewish community.

"There is absolutely no justification for such acts of aggression against any community, regardless of the circumstances," president Rateb Jneid said.

Human rights commissioners condemned the attack "in the strongest possible terms".

"We are deeply concerned that this destructive and violent act will cause fear and intimidation and exacerbate trauma for the Jewish community," Race Discrimination Commissioner Giridharan Sivaraman said.

Officers were told two men were inside the synagogue where the masked assailants poured liquid on the floor.

Police believe the attack was targeted and renewed an appeal for information.

Detective Inspector Chris Murray said police were not ruling out terrorism as a motive, as they search for the suspected arsonists.

"We are throwing everything at this," he told reporters outside the synagogue on Friday.

Founder of Yumi's dips, Yumi Friedman, was inside and described a "big bang on the door with a sledgehammer", before he fled to call help.

He returned to find the synagogue was fully alight.

"I touched the door, it was hot and I burnt my hand so I didn't go inside," he told AAP.

Fellow congregant Ruvi Herzogtold told AAP: "It's devastating, right to the heart of the community, to go and to know that you're not safe."

Glen Eira is home to one of the largest Jewish communities in Victoria with 25,585 people, according to state government data.