A worshipper thought he was in the middle of a terrorist attack when masked assailants set one of Melbourne's largest synagogues alight.
Yumi Friedman, founder of Yumi's dips, was preparing for morning prayer in the Adass Israel synagogue at Ripponlea about 4am on Friday when the attack occurred.
"I heard a big bang on the door with a sledgehammer, it looked like," he told AAP at the scene, in southeast Melbourne.
"I stopped for a second, and then suddenly heard another bang on the glass, and I saw glass fling. So I knew someone was out there trying to break in."
Mr Friedman fled the building to call police before returning to find the synagogue alight.
"There wasn't much of a fire when I started, so I just thought maybe I would come inside to get my phone," he said.
"But I touched the door, it was hot and I burnt my hand so I didn't go inside."
The fire quickly tore through the synagogue, engulfing it in flames and gutting two out of its three buildings.
Mr Friedman said his mind immediately turned to the attack being an act of terror.
"This happens in Israel every day, and Australia is going against it," he said.
"I want to live a normal life. I've got a big business, I don't need all this."
Fellow congregant Ruvi Herzog said the community was lucky Mr Friedman was studying and could sound the alarm.
"It is one of the most active synagogues in Melbourne and it's devastating, right to the heart of the community, to go and to know that you're not safe," he told AAP.
"Look at the age of the kids standing outside here; you've got 13-year-olds and 14-year-olds and eight-year-olds ... everybody comes here."
The City of Glen Eira is home to one of the largest Jewish communities in Victoria with 25,585 people, according to state government data.
Earlier, Fire Rescue Victoria's assistant chief fire officer Brayden Sinnamon said two people were evacuated with minor injuries, and no other properties were damaged.
The fire was brought under control just before 5am and Victoria Police launched an investigation to find two suspected arsonists.
Arson and explosives squad Detective Inspector Chris Murray said officers do not know the motive but a witness saw two masked offenders in dark clothes.
"They appeared to be spreading accelerant of some type inside the premises," he told reporters.
"This individual has left, police were subsequently called to the premises, where the premises had been engulfed and has suffered extensive damage."
Furious community members heckled Det Insp Murray as he addressed the media outside the place of worship on Friday morning.
"People have been attacked here. Why don't you put someone in here?" a man who identified himself as Yossef said.
"We're doing our best," Det Insp Murray replied.