PARIS (Reuters) - Thirteen members of a radical Islamist group arrested in police raids last week are being put under investigation on suspicion of terrorist activities, a public prosecutor said on Tuesday.
Nine of them will be held in custody during the inquiry, Paris prosecutor Francois Molins told a news conference, adding that the suspects had at one time discussed the possibility of kidnapping a judge in the city of Lyon.
Those under inquiry were among 19 arrested in swoops across several cities on March 30, a week after police killed Mohamed Merah, an al Qaeda-inspired gunman who shot dead seven people, including three Jewish children, in three separate attacks.
The killings turned internal security into a bigger campaign issue ahead of the April 22 opening round of a vote in which President Nicolas Sarkozy is seeking a second term but trails in the opinion polls behind Socialist rival Francois Hollande.
Prosecutor Molins said those placed under investigation on Tuesday were suspected of belonging to Forsane Alizza, a recently outlawed group that came to prominence after calling in 2010 for a boycott of a McDonald's outlet, accusing the U.S. fast food chain of serving Israel.
Forsane Alliza's leader, Mohamed Achamlane, was among those put under investigation after raids in which police found a range of weapons including Kalashnikov assault rifles.
"Let me tell you firstly that there is no link between this affair and the Merah affair," said Molins. The Forsane Alizza raids were prompted by police work begun last year, he said.
Sarkozy nonetheless drew a link between the two affairs during a television interview on Tuesday in which he vowed to root out any form of militancy following Merah's killing spree.
"We've decided it's zero tolerance," he said on Canal+ TV.
(Reporting by Brian Love and John Irish; Editing by Alistair Lyon)