The Supreme State Security Prosecution ordered on Sunday the detention of six suspects for 15 days pending questioning over the assassination of former chief prosecutor Hesham Barakat.
The suspects were arrested on Saturday evening and are being investigated in connection with premeditated murder, joining a terrorist organization and possessing weapons and explosives.
The six suspects belong to the Sinai Province terrorist organization (formerly known as Ansar Bayt al-Maqdis), judicial sources told Al-Masry Al-Youm.
Barakat was appointed as chief prosecutor following the ouster of Islamist President Mohamed Morsi in 2013.
Barakat died of his injuries after a bomb attack on his car in Cairo on June 29, 2015. The car bomb struck his convoy as it was leaving his home in Cairo.
Initially, sources said a car bomber had rammed into the convoy. Later, they said the car bomb was detonated remotely. Two civilians and two policemen were also wounded.
A little-known group calling itself the "Giza Popular Resistance" had claimed responsibility for the attack on its Facebook page, but the claim was taken down a few hours later.
Prior to the attack, the Islamic State's Egypt affiliate Sinai Province urged followers to attack judges.
The Sinai Province group was initially known as Ansar Beit al-Maqdis, but changed its name in 2014, after it pledged allegiance to the Islamic State group.
Sinai Province claimed responsibility the killing of three judges in the northern Sinai city of Arish in May 2015.
