This article is published in partnership with Time.com. The original version can be found here.
By Conal Urquhart @conalu
French officials are confirming an explosion at a factory near Grenoble in what appears to be a terrorist attack.
A body of a decapitated man was found close to the entrance to a site operated by a subsidiary of Allentown, Pa.-based Air Products & Chemicals Inc. (APD), a maker of industrial gases and chemicals. His head was was found nearby. A flag of the Islamic State in Iraq and Greater Syria (ISIS) has also been found.
One man, said to be in his thirties and well known to the French internal security service, has been arrested. Bernard Cazeneuve, the Minister for the Interior has arrived at the scene of the explosion.
A French security official told the Associated Press that two attackers arrived in a car, bearing banners written in Arabic, crashed into gas cannisters triggering an explosion. One man was arrested and the other escaped.
According to Le Dauphiné Libéré, the local newspaper, the decapitated head was covered in Arabic inscriptions and was hung on a fence. A security official told the paper that they had been expecting an attack somewhere in France in recent weeks.
The French Prime Minister Manuel Valls has ordered that security should be increased in the Rhône-Alpes region where the incident happened.
The attack appears to be the most serious in Europe since the mass shooting of staff at the satirical magazine Charlie Hebdo by terrorists in January in Paris.