Security officials say a car bombing has targeted the convoy of Egypt's Interior Minister in Cairo's Nasr City district.
They say the minister, Mohammed Ibrahim, has survived the attack.
They said it was not clear whether Thursday's late morning explosion was caused by a suicide car bombing or an explosives-laden car detonated by remote control.
The Interior Minister is in charge of the country's police force.
Nasr City is a stronghold of the Muslim Brotherhood, the Islamist group from which ousted President Mohammed Morsi hails. It was also the site of a sit-in protest by his supporters that was stormed by police on Aug. 14, killing hundreds.
The officials spoke on condition of anonymity because they were not authorized to speak to the media.