Australian police have said they are hunting for three suspects over an arson attack on a Melbourne synagogue, designating it a terrorist act, AFP reports.

Mask-wearing attackers set the Adass Israel Synagogue ablaze before dawn on Friday, police said, gutting much of the building. Some congregants were inside the single-storey building at the time but no serious injuries were reported.

Police have “three suspects in that matter, who we are pursuing”, Victorian police chief commissioner Shane Patton told a news conference. Investigations over the weekend had made “significant progress”, Patton said, declining to provide further details of the operation.

Officials from the federal and state police, as well as Australia’s intelligence agency, met today and concluded that the fire was “likely a terrorist incident”, the police chief said.

“Based on that, I am very confident that we now have had an attack, a terrorist attack on that synagogue,” he said. Counter-terrorism police have joined the probe.