A shop manager was threatened with a drill bit by a robber in Dudley Street.
A man entered JJ Foods between 9am and 9.10am and threatened the 39-year-old manager, asking for cash.
He tried to grab the till and the manager sounded the shop alarm system, causing the offender to flee the scene empty-handed.
Det Con Matt Shepherd said: “This was a shocking incident for the victim.”
The offender is described as a white man in his 30s wearing a blue UCLA hooded top. Call 101 with information.