Meanwhile, Mr Bowman said Police were still continuing their inquiries into an aggravated robbery at the Elles Road Night 'n Day store on 15 November.
Police said shop owners should "be mindful of their own safety" and co-operate if confronted with a similar situation.
"It's important to stay calm, obey what an offender is saying but also to observe as much as possible to obtain a description of the offender or the direction they leave in," Mr Bowman said. "It's also important to preserve any evidence."
Mr Bowman said people with any information about this morning's aggravated robbery should telephone Detective Scott McConachie on 03 211-0450. Police said information could also be provided anonymously to Crimestoppers on 0800 555 111.