Prosecutors have ordered the detention of two policemen for negligence after a bomb exploded inside a Cairo court, Al-Ahram Arabic news website reported.
The homemade bomb exploded in the prosecution room, injuring a prosecutor and his secretary.
The two officers will be held for four days pending investigations into the incident.
The explosion happened while the prosecutor was examining confiscated materials in a case involving sabotage at a telecom centre.
Bombings and shootings have surged since the ouster of Islamist president Mohamed Morsi last year.
Major attacks, mainly targeting security forces and installations, have been mostly claimed by radical Al-Qaida-inspired groups based in the Sinai Peninsula.