By Nicolas Bertin and Thierry Lévêque
PARIS (Reuters) - A French Muslim convert convicted in 2007 for planning an attack on an Australian nuclear plant is one of the suspected militants being held for questioning after a series of raids throughout France, a police source said on Saturday.
Willy Brigitte was arrested on Friday at his home in Asnieres, a northwestern suburb of Paris. Authorities found no weapons but seized his computer and a mobile phone, the source told Reuters.
The crackdown followed a pledge by President Nicolas Sarkozy, who is three weeks away from the first round of presidential elections, to rid France of radical Islamists.
His public approval rating has edged up slightly due to what most French believe to be his able handling of this month's killing spree by an al Qaeda-inspired gunman in Toulouse.
The latest raids by masked police commandos were not linked directly to the rampage in southwestern France, a police source has said, but they have still sent a strong message of force as security issues shot up to the top of agenda ahead of the vote.
On Saturday, authorities extended their detention of 17 suspects, including Brigitte, held for questioning, a judicial source said. A normal detention period of 24 hours under French law can be extended up to 96 hours in terrorism investigations.
The head of the DCRI domestic intelligence agency, Bernard Squarcini, told La Provence daily in an interview published on Saturday the suspected militants were planning a kidnapping.
"They appeared to be preparing a kidnapping. As regards their financing, we're waiting for them to explain themselves," he told the newspaper.
Brigitte was convicted by a French court in March 2007 for plotting an attack against the Lucas Heights nuclear research facility outside Sydney. He was sentenced to nine years in jail.
Australia, targeted by Islamist militants for its role alongside U.S. forces in Iraq and Afghanistan, had deported the Islamic convert, originally from the French territory of Guadeloupe, to France in October 2003 after he breached his tourist visa, before any attack could be carried out.
It was not immediately clear whether Brigitte's sentence had been reduced and he had been released before Friday's arrest. At the time of his sentencing, a judge said he should serve at least six years.
An after-hours message left with a court spokeswoman was not immediately returned.
During his trial in France, prosecutors said that after converting to Islam in 1998, Brigitte joined a group conducting military-style training in Fontainebleau forest near Paris and later graduated to weapons and explosives training in camps on the Pakistan-Afghan border.
He spent 2-1/2 months in 2001/2002 in a training camp for Lashkar-e-Taiba, a group with ties to al Qaeda.
Prosecutors said Australian police had found in his pocket a printout of an Internet page on nuclear and military facilities in Australia. Brigitte's lawyers maintained during his trial that he was the victim of an Islamophobic witch-hunt.
During Friday's operation - in which 19 suspects were arrested, according to Sarkozy - authorities seized a total cache of five rifles, three Kalashnikovs, four handguns and a bullet-proof vest. But a source close to the investigation said on Saturday that the Kalashnikovs had been disabled.
Interior Minister Claude Gueant has said the suspects received paramilitary-type training, but did not say whether they were planning an attack.
Mohamed Merah, the Toulouse gunman, was killed by police last week after shooting dead three Jewish school children, a rabbi and three soldiers in attacks around Toulouse.
(Reporting By Nicolas Bertin and Thierry Leveque. Writing by Alexandria Sage; Editing by Maria Golovnina)