France opened a terrorism investigation after an attack at a gas factory Friday left one person decapitated and multiple people wounded, officials said. One official said banners with Arabic writing were found near the body.

Two French officials said the attack began mid-morning when two men crashed a car into the entrance of a gas factory in Saint-Quentin-Fallavier in southeastern France, hitting gas canisters and touching off an explosion.

One of the attackers was arrested, they said. It was unclear what happened to the other attacker.