At around 3:15pm on Monday a cash-in-transit van arrived at a restaurant on Brandleshome Road and the driver went inside.
Whilst he was inside, a black Audi reversed onto the pavement next to the van and waited for the man to come out.
As the driver exited the building, two men – one of whom was armed with a hammer - got out of the Audi and threatened him before taking the cash box that he was carrying.
The offenders then fled the scene seemingly unaware that the cash box was empty.
Detective Constable Mark Robertson, of GMP’s Bury borough, said: “Although the men didn’t get away with any cash, they still subjected another person to a terrifying ordeal as he was trying to go about his daily business.
“This simply cannot be allowed to happen and we are keen to speak with anyone who may have information that can help us find the men responsible.
“If you think that you can help then I would encourage you to please contact police.”
Anybody with information should contact police on 0161 856 8223 or the independent charity Crimestoppers, anonymously, on 0800 555 111.