Three men forced staff to open up the store and let them into the safe.
One of the men fired a handgun and the bullet “skimmed the back of a male member of staff, causing minor injuries”, West Midlands Police said.
Another member of staff also suffered minor injuries. Both staff members were taken to hospital and treated.
The robbers escaped on foot with a large amount of cash. All three had their faces covered and wore dark clothing, the police said.
They are appealing to the public for witnesses or information.

