A bomb exploded near a school in the northeast Cairo district of Nasr City's 7th Zone, Al-Ahram's Arabic news website reported.
The accident left no casualties or any damage to surrounding buildings, Ahram added.
The area was cordoned off as security forces and explosives experts were enlisted to assess the situation.
Initial investigations showed that a home-made bomb composed of "mortar, gunpowder and nails" caused the explosion.
In related news, a raging fire broke out at El Nasr Company for Electronics (Niaza) in Egypt's coastal city of Alexanria leading to 31 injuries so far, reported Al-Ahram's Arabic news website.
The injured were carried to a nearby hospital as firefighers continue to attempt to extinguish the fire.
