Egypt's interior minister, Mohammed Ibrahim, has survived a car bomb attack on his convoy as it travelled through the Nasr City district in Cairo.

Security officials are not yet clear whether the explosion on Thursday morning was caused by a suicide car bombing or an explosives-laden car detonated by remote control.

Ibrahim 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 Mohamed Morsi hails. It was also the site of a sit-in protest by his supporters that was stormed by police on 14 August, killing hundreds.