A car bomb exploded in Cairo on Friday unsuccessfully targeting a judge who is trying a case against supporters of ousted president Mohamed Morsi, a security source told Ahram Online.

The incident took place in the district of Nasr City and was aimed at judge Ahmed El-Fotouh, according to the source.

Another security source told Ahram's Arabic website that there were no casualties. 

Explosives experts were dispatched to the scene to investigate the incident.

The prosecutor-general has ordered the opening of an investigation into the incident, and a team from the prosecution is on the scene to examine evidence.

In late September, a car bomb targeting one of the top prosecutor's assistants exploded in a suburb of Cairo, but failed to harm the senior judge.

In May last year three bombs exploded outside the Cairo home of another judge known for presiding over trials of Islamists, injuring four bystanders.

In June 2015, prosecutor-general Hisham Barakat was killed when a bomb hit his car convoy, also in Cairo.