Sydney church fire 'heartbreaking'

Church treasurer Steve Kostovski has enjoyed countless weddings and christenings at the Macedonian Orthodox Church of the Resurrection in Sydney's south.

But a day after Easter celebrations in the historic building, the dedicated parishioner is devastated.

The Rockdale church, parts of which have been standing since the 1890s, was engulfed in flames around 10pm on Sunday, less than 12 hours after the end of the Easter service.

Mr Kostovski says there were irreplaceable icons from around Europe inside and the church did not have contents insurance.

"It is heartbreaking," an emotional Mr Kostovski said as investigators took pictures of the rubble from a cherry-picker on Monday.

"The name of the church was resurrection of the Christ. It makes it even more sad because yesterday was the resurrection of Christ."

Witnesses have said the huge blaze, which caused minor damage to a nursing home next door, took hold quickly.

Three firefighters were injured and two were taken to hospital after being struck by falling bricks.

The emergency workers and two nursing home residents, who were treated for minor smoke inhalation, have since been released from hospital.

File Veljanov, who says he goes to the church every day, was told about the fire after his daughter saw it on the internet.

He told AAP that onlookers, many from his flock, cried as flames continued to burn around 1am.

"Emotions cannot describe," he told AAP through a translator on Monday.

"People were shocked, tears, (they were) emotional."

Around 60 firefighters battled to contain the flames that burst through the roof and forced the evacuation of 60 residents from the nursing home.

It was not the only fire in Orthodox churches over the past 24 hours.

In Melbourne, Australia's second-oldest Greek Orthodox church was saved after a fire broke out on Monday, while in the US, a Serbian Orthodox church has reportedly been gutted in New York.

The displaced Sydney congregation has received support from nearby Catholic and Uniting churches, which have offered their buildings for the congregation to hold a mass.

Mr Kostovski says the old building had been leased by the Macedonian community for around 15 years and the church doesn't know if it will rebuild.

NSW Fire and Rescue commissioner Greg Mullins said the result could have been much worse.

"Every window of this side of the fire has been cracked by the heat," he said.

"Great work by firefighters tonight - this nursing home could have easily caught fire as well."

What's left of the building has not yet been deemed safe for investigators to enter.

An exclusion zone remains in place and a nearby kindergarten was closed on Monday.