A search was carried out in a Stevenage park on Tuesday evening after a man was approchaed by two males who had a bladed weapon.
Officers were contacted at around 5.45pm following the incident in St Nicholas Park off Pilgrims Way.
The informant reported that her 21-year-old son had been approached by two males, who then produced a bladed weapon.
Officers attended and conducted a thorough search of the area, but the suspects were not traced.
Nothing was taken and no one was physically hurt during the incident.
Enquiries are continuing at this time, and anyone with information is asked to contact Herts police on 101.
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