Egypt's Emergency State Security Criminal Court has adjourned Saturday a court hearing in the "Zeitoun cell" case to 17 June to complete pleadings.
Twenty-five are accused of adopting an armed jihadist ideology and committing an armed robbery at a jeweller's shop in Cairo's district of Zeitoun in 2008.
Four Copts were killed and two others injured in the robbery.
The trial was halted in March after defendants' lawyer requested that the case be returned to the prosecution in order to determine whether arrest warrants were legal, claiming that they were forged. They also requested that their defendants be tried before a civilian court.
These issues are yet to be finalised by the court.
State Security prosecution accused the defendants of forming a terrorist group called the "Regiment of Loyalty and Disavowal" (Sareyet Al-Walaa wa Al-Bara') that aimed to change the ruling regime by force.
The defendants were also accused of monitoring Egypt's oil pipelines and ship movements in the Suez Canal in order to plan attacks on ships.
The defendants remain in jail until court proceedings continue.