Anti-terror probe into French blast

A September 21 explosion destroyed a petrochemical plant and killed 29 people

PARIS, France (CNN) -- French anti-terrorist authorities say they are investigating a deadly chemical plant blast in the Toulouse area last month that authorities had said was an industrial accident.

A man found dead at the blast site was known to police for possible Islamic fundamentalist sympathies and was involved in altercations before the blast with workers displaying the U.S. flag in sympathy with victims of the September 11 terror attacks, authorities said.

The September 21 blast at the AZF petrochemical facility was believed to have gone off when employees accidentally mixed the wrong chemicals, fire officials said. The blast knocked out windows and damaged buildings several miles from the site.

Hassan Jandoubi, 35, a French national born in Tunisia, was found dead at the scene. He was dressed in several layers of garments, which the reports said were "in the manner of kamikaze fundamentalists."

Jandoubi was hired to work at the AZF plant by a subcontractor five days before the explosion.

Authorities said it took five days to get permission to search Jandoubi's apartment, a delay that hurt the investigation. When the apartment was entered, it was found cleaned out. There were no clothes or photos.

The blast killed 29 people, injured hundreds of others and damaged scores of buildings, including schools, hospitals, businesses and homes. According to the French Interior Ministry, 1,170 people were injured.

The blast also released an ammonia cloud, forcing the evacuation of the area immediately around the facility.

A nearby plant that manufactures rocket fuel for Arianespace, the French rocket company, suffered damage to its exterior.

Grande Paroisse, France's largest fertiliser manufacturer, sells its products under the AZF brand name, and is owned by Atofina, the chemicals unit of TotalFinaElf -- the world's fourth-biggest oil group.