Omar Diaby

Two teenage girls from the French city of Nice are being held on suspicion of planning an attack directed by a notorious Syria-based French terrorist, a source close to the investigation said on Sunday.

France's scramble to confirm the reported killing in Syria of a key Islamic State recruiter shows the headache authorities face in pinning down evidence of jihadists' deaths, which may be fabricated for strategic reasons, experts say.

Two teenage girls from the French city of Nice are being held on suspicion of planning an attack directed by a notorious Syria-based French terrorist, a source close to the investigation said on Sunday.

France's scramble to confirm the reported killing in Syria of a key Islamic State recruiter shows the headache authorities face in pinning down evidence of jihadists' deaths, which may be fabricated for strategic reasons, experts say.