AFP, PARIS: French police interrogated a suspected Islamist yesterday as they tried to piece together an attack in which the man put his boss's severed head on display in the second jihadist attack to hit France in six months. Prime Minister Manuel Valls, who cut short an official trip to South America, warned that France faced more attacks and that Friday's assault on a gas factory near the city of Lyon would increase tensions in the country and put citizens' resilience "to the test".
No jihadist group has claimed the French attack.
A suspect, Yassin Salhi, 35, was arrested after causing an explosion by driving a delivery van into a warehouse containing bottles of dangerous gas and chemicals at the US-owned Air Products factory in Saint-Quentin-Fallavier, 40 km  from Lyon.
The prosecutor in the case said Salhi was overpowered by firefighters as he was trying to open acetone bottles in what is believed to have been an attempt to cause a larger explosion.
The firefighters then discovered the decapitated body of his 54-year-old boss Herve Cornara -- who ran a delivery firm -- near the car, along with a knife. The victim's head was pinned to a nearby fence.