Possible links to organised crime are being examined after a fire that caused extensive damage to a Melbourne gym.
A car was used to crash through the front door of a Dandenong gym shortly after 3.30am on Sunday.
Victoria Police says those inside the vehicle then poured accelerant through the building before setting it on fire.
A burning car, believe to be linked to the fire, was located in a nearby street.
Detectives are treating the incident as targeted and are investigating whether the blaze is linked to a series of arson attacks by Middle Eastern Organised Crime groups and outlaw motorcycle gangs.
A war between Middle Eastern organised crime gangs is suspected to be behind 11 earlier firebombings across Melbourne.
Victoria's three biggest squads are investigating Sunday's fire and Inspector Chris Murray said police were responding accordingly.
“Any escalation means an escalation in our response," he told reporters at the scene.
“Its quite unusual that we pull three of the biggest squads in crime command together.
“If you’re behind this, if you’re associated with this, the people involved in this, we will be paying you a visit. Mark my words.”
While the fire didn't reach neighbouring businesses, it is believed they suffered significant smoke damage.