Officers were alerted to the incident at 7.15pm yesterday, Tuesday 12 December, shortly after a suspect had walked out of the Shell petrol station in High Street, having stolen cash and cigarettes.
The suspect, who is believed to be male, entered wearing dark jeans, a light-coloured hooded top with the hood up, as well as a black ski mask with small eye holes. He was holding a handgun, while he also pulled out a knife from his waistband, before putting a large, army-style, camouflaged rucksack onto the counter and telling a staff member to fill it with cash and cigarettes.