The trials will involve 700 suspects. Some are directly linked to the attacks. Others belong to groups which have been preparing acts of violence in the country, Justice Minister Mohamed Bouzoubaa told state television.
The trials, to begin on Monday, will be conducted in Casablanca and in the capital Rabat.
The figure of 700 is more than four times higher than the number of Islamist suspects estimated by the independent press to have been arrested in police swoops around the country in the past two months.
The government has charged some suspects of having links to the al Qaeda network. Twelve suicide bombers were suspected to be involved in the five near-simultaneous explosions on May16.