A Giza security source said unidentified attackers hurled three bombs at police stations in eastern Mounira, western Mounira and Imbaba on Thursday.
"The three simultaneous blasts caused little damage to the police stations," the source added.
No casualties were reported.
Investigators said that at least six people were involved and that the bombs were thrown off motorcycles.
Meanwhile, an Interior Ministry source said a bomb went off inside a car stationed on Ahmed Saeed street in Abbasseya. Two persons were on board at the time.
An official statement by the ministry said police arrested one suspect, while the other one was able to get away.
Thursday marks the first anniversary of toppling former President Mohamed Morsy.
Edited translation from Al-Masry Al-Youm
