Gunmen shot dead three Egyptian judges and one civilian on Saturday in the strife-torn Sinai Peninsula, where security forces are battling armed groups insurgency spearheaded by an affiliate of ISIS, police said.
A car belonging to one of the slain judges was found containing the bodies of the three judges along with one civilian.
Witnesses said the car was targeted by masked gunmen.
The shooting in North Sinai's provincial capital El-Arish wounded two other judges and came hours after a court in Cairo sentenced ousted president Mohamed Morsi to death for his role in a mass jailbreak during the 2011 uprising.
Morsi received the capital punishment along with 106 other defendants ranging from Muslim Brotherhood leaders and members of the Palestinian group Hamas to the Lebanese militant group Hezbollah.
The cases, like any capital sentence, will be referred to Egypt's top religious authority, the Grand Mufti, for an opinion before any execution can take place. The last trial will be June 2, after the Grand Mufti has the last word.
No specific group has announced its responsibility for the attack yet.