MELBOURNE, Australia (AFP) — Mask-wearing arsonists set a synagogue ablaze in a pre-dawn attack Friday in the Australian city of Melbourne, police said, sparking widespread condemnation.

The fire broke out at 4:10 a.m. in the Adass Israel Synagogue when some congregants were already inside, police said, gutting much of the building in the southeast Melbourne suburb of Ripponlea.

No serious injuries were reported.

A witness entering the synagogue for morning prayers saw “two individuals wearing masks,” Detective Inspector Chris Murray of the Victorian police arson and explosive squad told reporters at the scene.

“They appeared to be spreading an accelerant of some type in the premises,” he said.

The synagogue was “engulfed in flames,” he added.

“We believe it was deliberate. We believe it has been targeted. What we don’t know is why.”

Police will increase patrols as they hunt for the arsonists, who were wearing dark clothing, he said.

Detectives would be looking at CCTV footage and interviewing any witnesses, Murray said.

Television images showed firefighters hosing down the embers through the blackened door of the single-storey building, which has a grey concrete facade.

A board member of the synagogue, Benjamin Klein, said a few congregants were sitting and praying inside when the fire started.

“They heard loud banging,” Klein told Agence France-Presse.