Suspects in France who allegedly carried out a grenade attack on a kosher market are part of a major terrorist cell, a French prosecutor has claimed.
Francois Molins called the "active terrorist cell" the biggest threat of its kind that France has faced since the mid-1990s, when the Algerian-based GIA was dismantled.
Five of the 12 people arrested in raids around France on Saturday have been freed.
Seven people remain in custody, a day after police discovered bomb-making materials in an underground parking lot as part of a probe into the terrorist cell.
Mr Molins said he would pursue charges of attempted murder and terrorism against all the seven French citizens who are aged between 19 and 25.
The prosecutor added the profiles of the suspects detained in custody was "much more dangerous than we initially assumed" and said the probe had unearthed evidence they were planning 'jihad' in Syria and other countries.
The September 19 attack on the Jewish market in Sarcelles shattered windows and injured a customer at the store. Two attackers fled.
DNA traces found on the grenade led police to convicted drug dealer Jeremie Louis-Sidney, 33, who converted to radical Islam in prison.
Believed to be a leading member of the Islamist group, the suspect was killed in a shootout with police on Saturday.
Most of those fighting against Syrian President Bashar al Assad's regime are believed to be ordinary Syrians and soldiers who have defected, having become fed up with the authoritarian government, analysts say.
But increasingly, foreign fighters and those adhering to an extremist Islamist ideology are becoming involved in the war.
Two British nationals were arrested on Tuesday at Heathrow Airport on suspicion of supporting terrorism in Syria, possibly as part of a group that took two journalists hostage in July.
Authorities in France have been on high alert after a Frenchman who claimed links to al Qaeda shot and killed three Jewish children, a rabbi and three paratroopers in southern France in March.