On Sunday afternoon, Giza police evacuated the Virgin Mary Church in Al-Saff district after they found an improvised explosive device.
A bomb squad defused the device, but no further details were reported.
Coptic Christians, estimated at 10 percent of the population, are celebrating Palm Sunday amid tight security.
Egyptian police have been struggling against frequent bomb attacks since Mohamed Morsy's ouster in July 2013.
Since the 2011 revolution, several incidents of sectarian violence over church building, conversions and politics have taken place.