Police received a call at 21.40 on Friday 25 September reporting an incident at the bookmakers at the back of the Greyhound public house on Holt Road in Wrexham, where a member of staff had been approached by two young men demanding money.
The member of staff was threatened, as he closed the premises, with what is believed to be a large sledge hammer.
He challenged the men and they made off, empty handed, in the direction of Brooklands Garage in Wrexham.
No money was taken and no one was injured during the incident.
The two men, described as being in their late teens, were both wearing black and had their faces covered.
Anyone who may have witnessed the incident or who may have seen two young men acting suspiciously in the area is asked to contact Wrexham CID on 101 if in Wales, 0845 6071001 (Welsh line), 0845 6071002 (English line), Crimestoppers on 0800 555111 or text 66767
