Police are searching for a man after an armed hold up at a petrol station in Mosman Park last night.

The man allegedly entered the Shell petrol station on Stirling Highway just before midnight last night, and placed several items in his bag without paying.

When a staff member asked the man to pay for the items, he revealed a knife tucked into his shorts, before felling the scene on a bicycle.

He is described as 180cm tall, tanned skin, medium build and with a black beard and moustache.

The man was wearing black shorts and a black t-shirt, with a black baseball cap.

Anyone with information is asked to call Crime Stoppers on 1800 333 000 or to make a report online at crimestopperswa.com.au.

Extracted in Full from: Police search for man after armed hold up at Mosman Park petrol station | PerthNow