French police are reportedly still questioning a man suspected of carrying out an attack on a factory near Lyon, in which a man was found decapitated.
Yassin Salhi, 35, caused an explosion by ramming his car into an area containing flammable liquids, the BBC quoted prosecutors in Lyon, as saying.
His boss, the owner of a delivery firm, was found beheaded alongside Arabic inscripted flags.
Meanwhile, French President Francois Hollande is holding a security meeting with his ministers, and the nation is reportedly on a state of highest alert after the attack in the small town of Saint-Quentin-Fallavier, which is about 40 kilometres from Lyon.
Salhi is said to be a father-of-three, and was living in the Moines neighbourhood of the town. His wife, sister and another person into custody.