Five rights activists are on trial in Egypt over the torching of the campaign headquarters of a front-runner in the country's 2012 presidential election.

A court official says the proceedings opened on Thursday at the Criminal Court in Cairo but were later postponed to Sept. 3. The official spoke on condition of anonymity because he was not authorized to talk to the media.

Alaa Abdel-Fatah, a well-known blogger who was among the youth leaders in the 2011 uprising that toppled former President Hosni Mubarak, is among the five on trial.

They have been charged with arson in the attack on Ahmed Shafiq's campaign headquarters.

Shafiq, who lost the race to Mohammed Morsi, withdrew his initial complaint over the arson but the prosecutor general still went ahead with the case.