Paris attacks: `Twelve arrested overnight`
Police conducted raids in five towns in the Paris region, iTele reported.
Last week`s violence began with an attack on the Charlie Hebdo magazine.
A kosher supermarket and police were also attacked.
Police carried out raids in the towns of Montrouge, Grigny, Chatenay-Malabry, Epinay-sur-Seine and Fleury-Merogis overnight, iTele reported.
Meanwhile, German police say they have arrested two suspects following raids on suspected Islamist sites early on Friday.
Neighbouring Spain has also launched an inquiry after it was revealed that one of the Paris gunmen, Amedy Coulibaly, had visited Madrid days before the attacks.