London, UK (BBN)– French President Francois Hollande confirmed that a Friday incident at a factory in southeastern France was a “pure terrorist attack.”

Hollande said a body had been found, along with a severed head with a message. He said a suspect had been arrested and identified. A man arrested at the scene is refusing to talk, CNN’s French affiliate BFMTV reported. He has no identification papers on him.

A suspected Islamist attacker pinned a severed head covered with Arabic writing to the gates of a gas factory in southeastern France on Friday, the CNN reported quoting French news agency AFP.

One person is in police custody and is suspected of involvement in the attack — which also involved at least one explosion — Joelle Huillier, a local politician, told BFMTV. He is being questioned by police, she said.

A source cited by BFMTV also said a severed head had been put in front of the company, next to which was found an Islamist flag. CNN has not been able to confirm the report independently.

A man described as a witness, whose name was given as Patrice, also told BFMTV that a group of men carrying Islamic flags forced their way into the factory, beheaded a person and targeted gas tanks.

Le Monde newspaper cited unidentified sources as saying that two people rammed a vehicle into the building, causing the explosion. Banners in Arabic that haven’t yet been examined were found at the scene, the paper added.

The Paris prosecutor’s office said its anti-terrorist section was opening an investigation into the attack.

It is investigating possible murder and assassination attempts by organized gangs in relation to a terrorist enterprise; destruction and degradation resulting from explosive materials by organized gangs in relation to a terrorist enterprise; and terrorist conspiracy to commit crimes against people, the Paris prosecutor’s office said in a statement.

A spokeswoman for the company concerned, Air Products, confirmed there had been “an incident” at its Grenoble location.

Spokeswoman Nicola Long said emergency services were at the scene. There was an explosion, she said, and a fire that has been put out.

She was not able to give any information on any deaths or injuries. The company supplies gases for industrial use.

Interior Minister Bernard Cazeneuve is making his way to the scene in the small town of Saint-Quentin-Fallavier, between Lyon and Grenoble.

President Francois Hollande, who’s been at a summit of European leaders in Brussels, Belgium, will give a statement in the afternoon, the Elysee Palace said.

Security has been heightened in France since an Islamist terror attack in January, when attackers targeted the satirical Charlie Hebdo magazine and a kosher supermarket in Paris.

BBN/SSR/AD