Five women wearing the Islamic headscarf have been prevented from entering a nursery school in Corsica by other parents, local media report.
Police intervened to calm the incident in Bonifacio, local media reported.
Staff and pupils at French schools are banned from wearing religious symbols – but parents are not.
Tensions between Muslims and other locals have been simmering in southern France, particularly after a jihadist in a lorry murdered 86 people in Nice.
Monday’s incident in Bonifacio took place as children returned to school after the summer holiday.
The parents who blocked the women said they were unhappy because their children were reprimanded if staff saw their Christian crosses.