French officials have rounded up suspects who may have been involved in Friday's attack on a gas plant where a man was found decapitated. Sean Carberry reports.
STORY: French authorities are piecing together the details of the attack on a U.S.-owned gas plant in southest France. It's believed that the suspect, Yassin Sahli, was making a delivery to the plant with his boss. Sahli then allegedly killed and decapitated him. An Islamist flag was found along with the body. Arabic writing was scrolled on the severed head. Officials say Sahli then rammed the delivery truck into the plant, injuring two people. Sahli survived and was arrested. Police have also detained suspected accomplices as well as Sahli's wife. She earlier gave a radio interview, claiming they were an ordinary Muslim family. But Sahli had been under surveillance for having ties to radical Islamist groups. French President Francois Hollande described it as a terrorist attack and is calling for unity...and vigilance.. (SOUNDBITE) (French) FRENCH PRESIDENT FRANCOIS HOLLANDE, SAYING: "The French people should know that security forces are today deployed on a scale not seen in our country for decades." This attack took place barely six months after Islamist gunmen killed 17 people in a series of attacks in and around Paris in January. And, for the second time this year, France has been forced to raise its terror warning alert to the highest level.