The 15-year-old girl apparently disappeared without a trace at around 5.30pm on Friday afternoon after her moped was left at a friend's house some 10 kilometres from her home, according to the Midi Libre daily.
The moped was found at around 10pm with a cold engine.
The girl's picture has been placed in public places around the medieval town and surrounding villages as the search is set to enter its fourth day on Tuesday.
An area of 16 square kilometres has been combed around Barjac since the search began, but no cluse have emerged as to the teenager's whereabouts.
Chloe's mother has revealed that her daughter may have been in a state of emotional distress at the time of her disappearance.
The girl is described as being 1.59 metres tall, with a slim build, blue eyes, long light brown hair and pierced ears. At the time of her disappearance she was wearing jeans and a beige Adidas jacket with black sleeves.
Police in Barjac have called for any witnesses to contact a hotline on 04.66.24.50.27.