The referendum's operations chamber in Giza detected a suspicious foreign object near al-Shorouk school in the neighborhood of Bulaq al-Dakrour.
Explosives experts rushed to the scene and discovered that the object was a hand-made bomb.
No one was hurt and no other bombs were found.
Authorities are on high alert as a bomb exploded outside North Giza Court on Sudan street on Tuesday.
Investigators said that five bombs were also found outside polling stations in Minya.
Edited translation from Al-Masry Al-Youm
