Paris - The French authorities yesterday questioned a 35-year-old delivery man of North African origin over a suspected terrorist attack involving the beheading of his boss and an attempt to blow up a United States-owned chemicals plant in south-eastern France.
President Francois Hollande, dealing with new security fears less than six months after 17 people were killed by terrorist gunmen at satirical weekly Charlie Hebdo, in a southern Paris suburb and at a Jewish foodstore in Paris, said the incident amounted to a terrorist attack.
Yassin Sahli is suspected of having rammed his delivery van into a warehouse of gas containers, triggering an initial explosion.
He was arrested minutes later while opening canisters containing flammable chemicals, prosecutors said last Friday. Police later found the head of the 54-year-old manager of the transport firm that employed the suspect, dangling from a fence at the site, framed by flags with written references to Islam.
Sahli was being held in Lyon, where he refused to respond to interrogators yesterday, according to a source. His wife, sister and another man are also in detention.
The second man is being investigated on terrorism-related charges but his link to the attack is not clear. Paris public prosecutor Francois Molins said there was no indication that Sahli had an accomplice.
Interior Minister Bernard Cazeneuve said last Friday the father of three had been investigated for links to radical Salafists, fundamentalists who follow a strict interpretation of Islamic law, in Lyon. However, Sahli was not identified as having participated in terrorist activities and had no criminal record. Speaking after a meeting yesterday with Mr Hollande, Mr Cazeneuve vowed the government would "continue to work relentlessly" against terrorism.
While an anti-terrorist inquiry has been launched, Mr Molins said it would be premature to make any conclusions at this stage and investigators had yet to fully understand what happened at the industrial zone in Saint Quentin-Fallavier, 30km south of Lyon.
"Questions remain over the exact chronology of events, what happened when he arrived, the circumstances of the decapitation, the motivation and whether there were accomplices," Mr Molins said.
No terrorist group has claimed the French attack which came on the same day as a massacre at a Tunisian beach resort in which 38 people were gunned down, and a suicide bombing in Kuwait that killed 27. The other two attacks have been claimed by the Islamic State in Iraq and Syria (ISIS) group.
However, the French authorities said there was no established connection between the attacks and no indication that the site had been targeted because of its US owner, industrial gases and chemicals group Air Products.
While Sahli's Islamist connections were known to the authorities, neighbours at his family home in a quiet Lyon suburb expressed disbelief.
"They are a very normal family," a 46-year-old housewife said. "I only talked with madame. He didn't say hello or goodbye," she added.
A co-worker described Sahli as "a wolf in sheep's clothing" to RTL radio, adding that Sahli had spoken to him about ISIS - "not to try recruit me for anything but simply to ask my opinion".