Twelve suspects are being held by police in the Paris region over last week's attacks in the French capital that killed 17 people, reports BBC.
They are being questioned about "possible logistical support," such as weapons or vehicles, they could have given the three gunmen, police say.
Police conducted raids in five towns in the Paris region.
Last week's violence began with an attack by two gunmen on Charlie Hebdo magazine, which left 12 people dead.
A day later - on January 8 - a policewoman was shot dead by gunman Amedy Coulibaly while responding to a traffic accident in the south of Paris.
Four more people who were held hostage by Coulibaly were killed on January 9 when police stormed a kosher supermarket. Coulibaly was shot dead by police. Police also killed the two gunmen responsible for the Charlie Hebdo attack -- Said and Cherif Kouachi -- outside a warehouse near Paris earlier that day.
Three members of the magazine's staff were buried on Friday, including the editor Stephane Charbonnier, also known as Charb. Bagpipers played Amazing Grace at his funeral in the Pontoise district of Paris.
Mourners attend the funeral ceremony of French cartoonist and Charlie Hebdo editor Stephane "Charb" Charbonnier, in Pontoise, outside Paris (January 16) Scores of mourners attended the funeral of Stephane Charbonnier in the Pontoise district of Paris
In the latest development, police carried out raids in the towns of Montrouge, Grigny, Chatenay-Malabry, Epinay-sur-Seine and Fleury-Merogis overnight, iTele reported.
Also on Friday, the Gare de l'Est train station in Paris was evacuated for an hour over a bomb threat, train operator SNCF told the BBC. Services resumed at 09:00 local time (08:00 GMT), SNCF said, without giving further details.
French authorities say that about 120,000 police and soldiers are now mobilised across France and that anti-terror plans remain in place.
