Morocco said it has found no link between al-Qaeda and last week's suicide bombings in Casablanca that killed 41 people.
Justice Minister Mohamed Bouzoubaa said the 13 suicide bombers came from Casablanca's impoverished Sidi Moumen neighborhood.
Five blasts on Friday targeted Jewish and Spanish sites in Casablanca. The dead included three French nationals, three Spaniards and an Italian.
Mr Bouzoubaa had earlier pointed to the possible involvement of a little-known Islamist group called Assirat al Moustaquim (The Righteous Path).
Morocco was the Muslim country listed as "most eligible for liberation" in a tape believed to be from al-Qaeda leader Osama bin Laden. The tape, released in February, said any Arab leader who supported America would be "an apostate whose blood should be spilled." Morocco is a staunch ally of the United States.
"We took bin Laden's threats seriously," Mr Bouzoubaa said, "but what happened was committed by a group probably not known (to us), a group of very young people who were certainly misled by some people we're trying to identify.
"Was it because of bin Laden's statement or by chance this happened? The investigation will tell us if there is a link with bin Laden's organisation."
The Casablanca bombings followed the killing of at least 34 people last week in suicide attacks against Westerners in Saudi Arabia.