Updated

Security officials in Egypt say police defused two bombs overnight at Cairo International Airport, as a separate blast this morning in downtown Cairo scared passers-by without wounding anyone.

They say the airport bombs, one planted at the arrival hall of airport's terminal hosting EgyptAir and the other near a police patrol location, looked to be controlled remotely by mobile phone.

On Tuesday morning, officials say a sound bomb planted inside an electrical box in central Cairo exploded, wounding no one.

The officials spoke on condition of anonymity because they were not authorized to speak to journalists.

Egypt has been gripped by turmoil since the military toppled Islamist President Mohammed Morsi in 2013. The country has faced attacks ranging from suicide bombings to near-daily small blasts from homemade bombs.