At least three persons were injured, including a police officer, in the explosion in downtown cairo, state TV reported.
The area surrounding the building houses the General Prosecutor's office and is the headquarters of some of the country's most senior courts.
Egypt has witnessed many attacks targeting police and military personnel as well as civilians in the recent past.
The attacks have increased after the ouster of Islamist ex-president Mohammed Morsi in 2013.
Over 500 policemen and soldiers have been killed in the attacks.