Extremist quizzed over beheading
A suspected Islamic extremist is being questioned by anti-terror police after his boss was found decapitated at a gas factory in France.
The victim's severed head was hung from a post at the factory's entrance in Grenoble, on the outskirts of Lyon, with a message written on it, reportedly in Arabic.
French officials said two men in a car had earlier crashed into the factory site and ploughed into gas canisters in a hanger, sparking an explosion, just after 9.30am local time.
They named the suspected attacker as father-of-three Yassine Salhi, who was investigated in 2006 for his alleged ties to Islamic extremists and held under surveillance for two years.
Paris prosecutor Francois Molins said he was arrested after a firefighter found him opening gas bottles in a second hanger, and he was identified by workers who recognised him as a delivery driver.
French officials said Salhi's wife, sister, and a fourth person, are also in custody.
They said the victim was Salhi's employer, the head of a local transportation company.
His torso was found close to the factory site, while two flags with Arabic inscriptions were also discovered at the scene of the attack.
Two other people were injured in the incident which French president Francois Hollande described as having "the hallmarks of a terrorist attack".
The French leader, who was travelling back to France from Brussels, said there was "no doubt" the suspected terrorist meant to cause an explosion at the factory.
France would "never give into fear" and the attack must not "create unnecessary division", he added.
Police said Salhi is in his 30s and a resident of the Lyon suburb of Saint-Priest.
Earlier a woman claiming to be the suspect's wife had called French radio station Europe 1 to insist the family were "normal Muslims".
"My heart is going to stop," she said. "I do not know what has happened. Have they arrested him?"
The woman said her husband went to work as a delivery driver at 7am and she expected him home in the afternoon.
She added: "We are normal Muslims. It is Ramadan. We have three kids and a normal family life.
"Who can I call to give me more information because here I do not understand?
"I'm afraid to do anything."
A spokesman for US firm Air Products, which owns the factory, said: "Our priority at this stage is to take care of our employees, who have been evacuated from the site and all accounted for.
"Emergency services are on site and have contained the situation. The site is secure. Our crisis and emergency response teams have been activated and are working closely with all relevant authorities."
Prime Minister David Cameron expressed his sympathies over the incident to president Hollande as they attended a European Council summit in Brussels.
A Downing Street spokeswoman said: "He expressed his sympathies for what looks like an appalling incident.
"Details are still emerging, so we wait to see those. But it clearly looks an extremely concerning situation and our thoughts are with all those affected by it."
Mr Hollande has raised the security alert for the south-eastern region of France to its highest level for the next three days.
The country went on high alert in January after extremist brothers Said and Cherif Kouachi killed 12 people - including two police officers - in attacks on satirical magazine Charlie Hebdo in Paris.