French police arrested 19 suspected Islamist militants Friday in cities around the country, including Toulouse, hometown of extremist gunman Mohamed Merah.

Among other cities, raids were carried out in Toulouse's Mirail quarter and in Nantes, a center for the Forsane Alizza (Knights of Pride), a group with which Merah was affiliated, according to French media reports.

Merah, a 23-year-old French citizen of Algerian heritage, was killed last week by police after a 32-hour standoff prompted by the deadly shootings of seven people in southern France -- three French paratroopers of North African origin as well as a rabbi and three Jewish schoolchildren.

Those arrested Friday weren't believed to be directly linked to Merah, who was buried in Toulouse on Thursday, Agence France-Presse reported.

Speaking to France's Europe1 radio, President Nicolas Sarkozy said: It's our duty to guarantee the security of the French people. We have no choice. It's absolutely indispensable.

What must be understood, Sarkozy added, is that the trauma of [the recent killings] is profound for our country, a little -- I don't want to compare the horrors -- a little like the trauma that followed in the United States and in New York after the Sept. 11, 2001, attacks.

Sarkozy is currently embroiled in a tough re-election campaign in which France's handling of Islamic extremists has been an issue.

One of the people arrested Friday was the leader of Forsane Alizza, Mohammed Achamlane, according to AFP. It said three Kalashnikov rifles, a Glock pistol and a grenade were found at the man's home.

The nationwide raids were carried out by France's internal intelligence agency, the DCRI, and police commandos. Other cities raided were Marseille, Lyon, Paris, Nice, Rouen and Le Mans.

AFP quoted a police official as saying as many as 100 suspected extremeists could be targeted in future raids.

We have some extremely precise questions to ask a certain number of people and what happened this morning will continue, Sarkozy was quoted as saying by AFP. There will be other operations that will continue and will also allow us to expel from our national territory a certain number of people.