French security forces took at least 19 Islamists into custody in pre-dawn raids Friday, President Nicolas Sarkozy later told Europe-1 radio.
Sarkozy said police confiscated weapons, including AK-47 assault rifles, in some of the arrests. He said more operations are planned in the crackdown against suspected Islamic extremists.
The DCRI (French intelligence agency) and an elite police commando unit carried out the arrests, AFP reported.
Police raided several residences in Toulouse, the former home of Mohammed Merah, the 24-year-old Islamist who gunned down three children and a rabbi at the Ozar Hatorah Jewish day school there on March 20.
Raids also took place in Marseille, Lyon, Nice, Le Mans, Paris and Nantes, the former home of the Forsane Alizza (Knights of Glory) Islamist group, banned by French authorities in January for allegedly training members for armed combat.
Merah, who claimed ties to al Qaeda, had traveled to Pakistan and Afghanistan, possibly for training. He died during a shootout with police two days after the attack at Ozar Hatorah. The week before, he gunned down three French soldiers.
Police arrested Merah's brother, Abdelkader, who confessed to helping steal the motorcycle used the brutal attack at the school. He said he was proud of his brother.
Authorities are seeking a third accomplice, possibly the person who delivered the USB memory stick with footage of Merah chasing down eight-year-old Miram Monsonego, grabbing her by the hair and pumping three bullets into her head at point blank range.
The footage, recorded by a camera strapped to Merah's chest, was later delivered to the Paris bureau of al-Jazeera TV, which decided against airing it.