The gang, reportedly made up of eight 16 to 17-year-old girls, started shouting at the sisters as they were buying bread at their local bakery in the town centre.
“The eldest was seriously beaten up. She was thrown to the ground and kicked right in the face,” one member of the girls’ family told Le Parisien.
“While the little one shouted out in fear, they covered her eyes so that she couldn’t see her sister get beaten up, just hear her horrible cries.”
Both girls received medical attention at the scene from the emergency services, and were sent home to rest. They are to receive counselling later today.
After reporting the incident to police, the mother received a text message threatening her for having spoken to the authorities.
For now, the motive for the attack in unclear, but the sisters recognised a few girls in the gang.
Police investigating suspect “futile motive, like a love rivalry” may be at the root.