An improvised bomb detonated near a Cairo police training centre in the
Ain Shams district in east Cairo on Saturday morning.
No casualties were reported, an interior ministry spokesman said.
The blast came a day after a series of bombings targeting police across Cairo left six dead and tens wounded, and hours before Egypt is set to mark the third anniversary of the 2011 uprising that toppled autocratic president Hosni Mubarak.
Another bomb placed inside a vehicle in the vicinity of the building was defused, the official added.
The blast, which took place at around 7am local time only damaged the institute's façade, Ahram Arabic news website reported.
The attacks in the country's densly-populated areas have fueled fears that militant activity has moved beyond the border Sinai Peninsula, where militants have stepped up attacks since the ouster of Islamist president Mohamed Morsi in July.