Egyptian prosecutors referred 13 men to criminal court on Sunday on charges of killing two policemen and of belonging to outlawed militant group Ansar Beit El-Maqdis.
The defendants are accused of killing two police personnel and attempting to murder a third at a Cairo-Suez desert road checkpoint during an incident in April last year.
They are also accused of armed robbery of a post office and an ATM to finance their attacks, Al-Ahram Arabic website reported.
The Ansar Beit Al-Maqdis militant group is based in North Sinai and has claimed responsibility for a number of terrorist attacks in Egypt, most targeted at military and police personnel.
The frequency of militant attacks in Sinai and elsewhere increased dramatically since the ouster of president Mohamed Morsi in 2013.
A Cairo court for urgent matters labelled the group a terrorist organisation in April last year, and in November group leaders formally pledged allegiance to Islamic State militants based in Syria and Iraq.