According to police, the incident occurred around 9.15pm on Sunday at the Schueberfouer.
The thief discreetly stole a gold chain from a visitor's neck by patting him on the chest before quickly walking away.
It was only moments later that the victim realised his chain was missing. Together with a companion, he began searching for the suspect.
When they eventually found the individual, the suspect returned the stolen chain, though the pendant was still missing.
As the two men later confronted the suspect again at a nearby stall, the situation escalated. The suspect pulled out a pocket knife and threatened both men before fleeing in the direction of Allée Scheffer.
Despite a swift police search of the area, the thief was not located.
