Security guards discovered the package near a billboard in front of the store and alerted police.
Counter-terror units secured the area, advising nearby residents to stay indoors.
Bomb disposal experts from Wrocław transported the package to a nearby training ground, but no explosives were detected.
According to Radio Wrocław, police have detained a suspect. He is currently being questioned.
Unverified reports suggest that he drove to the supermarket at night and left computer parts intended for another person in the package. Security cameras show him doing this without covering his face.
An official statement on the matter is expected after questioning is complete.
(mp)
Source: Radio Wrocław