An attacker carrying an Islamist flag killed one person and injured several others Friday at a gas factory in eastern France, according to a legal source.

The suspected attacker entered the factory and set off several small explosive devices, the source said. A decapitated body was found nearby the factory, another source said.

"According to the initial findings of the enquiry, one or several individuals on board a vehicle, drove into the factory. An explosion then took place," said one of the sources.

"The decapitated body of a person was found nearby the factory but we do not yet know whether the body was transported to the place or not," added this source, adding that a "flag with Arabic writing on it was found on the scene."

A man thought to be the person who carried out the attack has been arrested, according to sources close to the enquiry.

Interior Minister Bernard Cazeneuve said he would go "immediately" to the scene, his office said.

The attack occurred around 10:00 am local time (0800 GMT), according to local media.

The attack came nearly six months after the Islamist attacks in and around Paris that killed 17 people in January that started with a shooting at satirical magazine Charlie Hebdo.

Two Islamist brothers attacked the satirical magazine, killing 12. A policewoman and four hostages in a Jewish supermarket were also killed during the three-day attacks.

The attacks drew record crowds out on the streets of Paris days in a historic "march against terrorism".