(Plastemart) -- A blast has been reported at a petrochemical site in Fos-Lavera of Compagnie Petrochimique de Berre, a unit of U.S. group LyondellBasell. The aftermath of the explosion and an ensuing spill of oil products have now been brought under control, as per Reuters However, traffic at the nearby oil terminal has not been affected. A spokeswoman at LyondellBasell said a fire started in a trench on the site of Compagnie Petrochimique de Berre and that an investigation was being carried out to find out what caused the blast.