Police say they do not have a motive for a fire which caused extensive damage at a clubhouse of the Rock Machine bikie gang in a southern Perth suburb.
Police say petrol was doused inside the Parkinson Lane premises in Kardinya and set alight just after midnight.
Damage to the building and gym equipment inside is estimated at $60,000.
Police say they do not know if the incident is linked to a fire that damaged a Rebels bikie gang clubhouse last month.
The Rock Machine gang is engaged in a long-running feud with rival Rebels.
Tensions between the gangs escalated in March this year when Rebels chief Nick Martin was shot outside his home in Balcatta.
A 30 year-old member of the Rock Machine has been charged with attempting to murder him.