have discovered a number of these devices, which consist of a .22 pistol
concealed within a hollowed-out cellular phone
They believe these came from in or near Yugoslavia. That's why travellers passing through security checkpoints at European airports are now required to send their phones through the X-ray machine. Three clues that the phone you're examining might be a gun:
a) if you can open it by twisting the ends in opposite directions,
b) if it will not light up or make a call,
c) if it seems abnormally heavy.