PARIS - An explosion in a Seveso-classified factory injured 3 people, including two in critical conditions, on Thursday at Saint-Julien-du-Sault (Yonne) in central France, local media quoted the prefecture as saying.

The accident occurred Thursday before 11:00 am local time (0900 GMT) in a storage building and is believed to be related to maintenance work for the company which specializes in the manufacture and design of sealing materials and insulation, according to the site France Info.

The prefecture said the fire was quickly extinguished by the staff and that "the situation returned to normal".