Police believe that the three offenders may have been responsible for a similar attack shortly before the robbery.
Detectives have received a report of an assault in the same location, which is believed to involve the same group of men.
A 17-year-old boy was punched in the face but managed to run off.
Officers are conducting enquiries in the area and would like to speak to anyone who may know who was responsible.
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Tuesday's weather for the west of the region
Tuesday's weather for the east of the region
The man who died as a result of a collision on the B4501 near Cerrigydrudion on Saturday, June 24th, has been named as Karl Ronald Hibberd.