Police are linking two potentially armed robberies which both took place in Banbury this week.
The first one occurred at the Esso petrol station in Ermont Way, Grimsbury, about 10.30pm on Monday when a man walked into the store and demanded money from the tills and from a customer who was being served at the time.
The member of staff and customer refused to hand over any money, so the offender left the store on foot.
The suspect has been described as white, about 5ft 10in tall, of medium build and aged in his 20s.
He was wearing a white Kangol hooded jumper with the hood up, cream trousers, black shoes, black gloves and a black scarf over his face.
The member of staff believed the offender was holding a black handgun and small black plastic bags.
The second offence happened at the Cooperative store in Ferriston about 8.45am on Tuesday when a man entered the store and demanded money from the tills.
A member of staff, who believed the offender was carrying a black handgun, handed over a sum of money before the suspect left the store on foot.
The offender has been described as white, about 5ft 8in tall, in his 30s and of skinny build. He was wearing a black hooded top and jeans.
No arrests have been made at this stage.
Detective Inspector Steven Raffield said: “I would appeal to anyone who saw anything suspicious in either area at the time of these offences to contact the police immediately on 101.
“I would like to reassure the public in Banbury that this type of offence is extremely rare, and that Thames Valley Police is conducting a thorough investigation to bring those responsible to justice.”
Those who do not want to speak to the police directly can call Crimestoppers anonymously on 0800 555 111 or visit www.crimestoppers-uk.org