Two men have used a blowtorch to threaten staff in a cinema in Perth's northern suburbs.

Police are searching for the men, who used the device and a fake gun to try to rob Grand Cinema in the Perth suburb Currambine just before 11:00pm yesterday.

The men, believed to be aged in their 20s, fled empty-handed after failing to break into the safe.

Cinema staff later told the police they believed the handgun was a fake.

Police are viewing security footage from the complex to try to identify the men.

They have asked anyone who noticed anything suspicious in the area last night to contact Crime Stoppers on 1800 333 000.