A French prosecutor says the beheading and attack on a French industrial gas factory bore the trademark of the Islamic State group.

Prosecutor Francois Molins said the man accused in the attack, Yassin Salhi, sent two photos of his employer's corpse to an acquaintance in Syria: One of himself with the severed head and the other of the body with the head placed on top.

Molins said the friend, Sebastien Younes, indicated Islamic State may distribute the photos as part of its macabre propaganda campaign to attract radicalized Westerners.

Salihi is accused of decapitating his employer then going to the U.S.-owned gas plant where he tried to crash his delivery truck into gas canisters and cause an explosion. He is under questioning on terrorism charges.