French Prime Minister Manuel Valls ordered heightening security measures on Friday at "sensitive sites" near the gas factory that was attacked in eastern France, News 24 reported.

Valls, who is on an official trip to South America, asked Interior Minister Bernard Cazeneuve to head for Saint-Quentin Fallavier, the site of the attack.

Cazeneuve was heading to the site in the town of Saint-Quentin-Fallavier, around 30km southeast of the city of Lyon.