The terror threat in France remains "very high", with 8000 people on the watchlist, the country's interior minister said, on the eve of the trial of the alleged Charlie Hebdo attackers.
Gérald Darminin warned of the threat, notably from Sunni extremists, as the authorities said that at least half a dozen plots have been foiled this year so far.
He was speaking as France prepared to stage its first trial since the attacks on the offices of the satirical magazine, Charlie Hebdo, in January 2015.
On January 7, 2015, brothers Saïd and Chérif Kouachi stormed the offices of the Charlie Hebdo magazine, killing 12 people, including cartoonists, other staff and a police officer in eastern Paris.
In the two ensuing days, another French Islamist, Amédy Coulibaly, killed policewoman Clarissa Jean-Philippe in a southern suburb and killed another four people in a Jewish supermarket just east of the capital.