A quick-thinking German bank employee used a smoke bomb early Thursday to drive off a band of criminals trying to break into a cash machine, police say.

Police said the thwarted robbers used explosives to try to blast open the cash machine in the western city of Witten at around 3.25 a.m. (0125 GMT), damaging the machine’s strongbox, as well as the building’s roof and windows.

The blast triggered an alert to a remote site handling the bank’s security.

Once workers ascertained by video link that a robbery was under way, they detonated a remote control smoke bomb prepositioned in the bank, prompting the robbers to flee empty-handed.

It is not clear how much the damage will cost to repair. (dpa/NAN)