French police commandos arrested 19 people suspected of radical Islamist activity in Friday morning raids in several cities including Toulouse, scene of the killings of seven people by an Al Qaeda-inspired gunman earlier this month.
President Nicolas Sarkozy, who is waging an uphill battle for re-election, said more raids would follow.
"There will be further operations, allowing us to expel a number of people who have no business in the country," he said in an interview on Europe 1 radio.
Gunman Mohamed Merah was killed by police snipers just over a week ago after shooting dead three Jewish school children, a rabbi and three soldiers in attacks around Toulouse, turning internal security into a bigger campaign issue ahead of the presidential election.
Polls showed that more than 70 percent of voters approved of Sarkozy's handling of the Toulouse shootings, which reduced his chief rival, Socialist frontrunner Francois Hollande, to the role of bystander ahead of the two-round election on April 22 and May 6.
A police source said about 20 had been arrested in raids in Toulouse in the southwest, Nantes in western France and also in the Paris region and southeast France. Sarkozy put the number of arrests at 19.
Several television channels showed images of the early morning raids. Commandos were seen bashing down doors, smashing windows, and taking suspects away with handcuffed and with their faces covered
French Interior Minister Claude Gueant said five rifles, three Kalashnikovs, four automatic handguns and a bullet-proof vest had been found among other items.
"These are people who ... claimed they were acting for an extremely violent, jihadist and combat ideology," Gueant told reporters after meeting Muslim associations in Paris.
"They had a paramilitary type of training," he said without confirming if those arrested were preparing attacks.
The swoops, carried out by the RAID police commando unit and anti-terrorist specialists, were not directly related to Merah's killing spree, according to the police source.
KNIGHTS OF PRIDE
Sarkozy, who ordered a crackdown on radical Islamists after the Toulouse killings, barred six Islamic preachers from entering the country on Thursday who wanted to attend a Muslim conference in Paris.
Gueant dismissed talk that the raids had been carried out in response to suggestions that the intelligence services had failed to monitor and track down Merah quickly enough.
The police source said the raids were not directly related to the investigation into the case of Merah, a Frenchman of Algerian origin, whose brother is under official inquiry and is in custody on suspicion of complicity.
The same police source said several of the people arrested were believed to be close to radical Islamist group called Forsane Alizza (Knights of Pride) that was recently outlawed. Gueant said the group's leader, Mohammed Achamlane, had also been arrested in Nantes.
Achamlane told the daily Liberation in January that the group could not exclude launching an armed struggle "if Islamophobia continues to intensify day by day".
Before the Toulouse attacks, the group was known for provocative demonstrations, such as protests last year against a French ban on worshippers praying in the streets and a ban on full-face veils.
Gueant dissolved the group in February, accusing it of preparing its supporters for armed struggle.
Gilles Kepel, political scientist and specialist in Islam, said the group operated more on the Internet - preaching extreme views and intimidating, but never actually turning to violence.
"It's a big show, but obviously spreading ideas that can cause problems," he said.
France's 5 million strong Muslim minority is the largest in Europe, but only a portion - about 10 percent, or the same proportion as among Catholics - are practising, according to Muslim associations.
(Additional reporting by Brian Love; writing by Brian Love and John Irish; editing by Geert De Clercq and Mark Heinrich)