The Australian Prime M;pinister says a synagogue was set on fire as an "act of hate" by arsonists who used a broom to spread accelerant.

About 60 firefighters and 17 trucks were called to the massive blaze at Adass Israel synagogue at Ripponlea in Glen Eira around 4.18am (6.18am NZ time) on Friday.

Prime Minister Anthony Albanese revealed accelerant was used and police had identified two people of interest.

"This is an outrage. It's clearly aimed at creating fear in the community," he told ABC Radio Melbourne.

"I have been briefed this morning by the AFP Commissioner Reece Kershaw, there are two persons of interest who were there.

"What was witnessed was them using accelerant and spreading it with a broom, clearly designed to maximise the damage that could occur."

Religious leader Rabbi Gabi Kaltmann said "two thugs" broke the synagogue's windows, threw fuel on the floor and set it alight as people were preparing to pray early Friday morning.

"It's outrageous," he told reporters at the scene of the fire.

"Tonight is the sabbath, we must all go and find a sense of calmness, comradery and community by gathering for the sabbath tonight and praying together as one community."

Attorney-General Mark Dreyfus said it was the responsibility of "every part of Australian society" to fight anti-Semitism.

"It has been surprising and deeply saddening to me how many times I have felt the need to say that fact over the past year," he said.

Earlier, Fire Rescue Victoria's Assistant Chief Fire Officer Brayden Sinnamon said the 30m by 20m building was "fully involved" in the fire and the blaze severity was escalated, with crews using breathing apparatus.

He said two people were evacuated with minor injuries but no other properties were damaged.

Police have asked anyone who witnessed the incident to come forward with information or dash cam/CCTV footage.