Regional Investigation Unit detectives are seeking information regarding four armed robberies in the Perth metropolitan area believed to have been committed by the same offender. About 9.05pm on Wednesday 12 January 2011, a man (pictured left) entered Douglas Discount Liquor in Redcliffe brandishing a large kitchen knife. He ordered a customer to get on the floor and threatened staff with the knife, demanding money. He stole cash and alcohol before fleeing the store on foot. About 5.20pm on Saturday 15 January 2011, a man wearing a balaclava (pictured right) entered the Perth Convenience Store on Victoria Avenue near St Georges Terrace, Perth. He threatened staff with a knife beforefleeing on foot with an amount of cash. About 7.50pm on Friday 29 July 2011, two men entered the Douglas Discount Liquor in Redcliffe. One of the men (pictured left) was armed with a knife which he used to threaten staff. The men stole cash, liquor and cigarettes before fleeing the store on foot. About 7.40pm on Monday 8 August 2011, a man armed with a knife (pictured right) entered the Celebrations Liquor Store in Kewdale. He threatened staff to open the til before stealing an amount of cash. He also ordered the staff members to lie on the floor until he fled the store on foot. The offender is described as fair skinned and between 165 and 170cm tall. In each incident, the man concealed his face with clothing wrapped around his head. Anyone with any information about these incidents or can identify the offender is asked to contact Crime Stoppers on 1800 333 000.