French law enforcement uncovered a plot by previously detained suspected Islamic militants to kidnap a Jewish magistrate and others, a source close to the investigation told AFP on Tuesday."It looks like some of them planned to carry out kidnappings including that of a magistrate who has a Jewish-sounding name," said the source.AFP quoted another source as saying that an additional target the group was after was a Jewish magistrate from Lyon in central France. The head of France's Central Directorate for Domestic Intelligence (DCRI), Bernard Squarcini, said on Saturday that the arrested Islamists were French nationals engaging in "war-like training, linked to violent religious indoctrination," according to AFP.He added that a number of the suspects were members of an extremist group known as Forsane Alizza. Forsane Alizza chief Mohamed Achamlane was to appear before anti-terror magistrates on Monday in Paris. The magistrates previously extended the detention of 15 other related suspects.Those suspects still in custody could be indicted on Tuesday, while three of the 19 people arrested Friday have already been released. French elite police arrested the suspects last Friday in several cities including Toulouse, the scene of this month's killings of soldiers and Jewish children, a police source said. The raids, less than a month from a presidential election, come just over a week after police hunted down and killed Mohamed Merah.The al-Qaida-inspired gunman admitted during a siege of his apartment that he had shot dead three soldiers, three school children and a rabbi in three attacks in Toulouse and the surrounding region.The police source said the raids were not directly part of ongoing inquiries into the case of Merah, whose brother Abdelkader has been placed under official inquiry and is being held in custody on suspicion of complicity.