Police are searching for a man who held up a Canning Vale service station at knifepoint this morning.
The man entered a service station on Bannister Road about 1.20am and started threatening staff with a knife.
He received an amount of cash before leaving the area in a vehicle, which was possibly blue.
It is believed the same man attended a service station on Belmont Avenue in Cloverdale shortly before midnight, where he stole several bottles of engine oil.
He later returned to the Cloverdale service station seeking a refund for the engine oil.
His request was denied.
Police described the man as 35 to 45 years old and 180cm tall with a fair complexion and short, brown hair.
Anyone with information is asked to call Crime Stoppers on 1800 333 000.